I passed the 1000km mark recently on my 2019 Quick E+ and thought an update was in order. The short summary is the Giant quick E+ is an awesome bike when it works BUT a pain in the backside when things go wrong, particularly if you live in NZ where we don't seem to have ready access to spare parts. I've now experienced most issues that have been outlined on this thread :-( If you are going to be using this as your main mode of transport make sure you are mechanically inclined and/or have a good local bike mechanic who knows their stuff, my bet is you will see them fairly regularly.
Here's a quick summary of issues I have experienced (with suggested resolutions where known). I've listed them in decreasing order of level of annoyance/hassle
1) My controller died on my first really wet ride, meaning I couldn't turn my bike on any more. My local bike shop had several other Giant E bikes with the same issue, so I suspect a manufacturing defect that allows moisture in. The bike shop said that for some of the other customers they had fitted a different controller (the ride control one
https://www.giant-bicycles.com/gb/showcase/ridecontrol-one ) to tide them over as the replacements were a while away. The ride control one doesn't come with a display but my mechanic hasn't heard of anyone having issues with that type dying in the wet. They didn't do that for me as replacement evo controllers would be arriving "soon" but unfortunately soon turned out to be 4 weeks :-( In retrospect I should have asked for the ride control one to be fitted while I waited, as a month without my main means of transport was super annoying. No issues with my replacement evo controller as yet, hopefully they found a way to make it water proof. If it fails again I'll be switching to the ride control one despite the fact it doesn't come with a display.
2) I developed issues with not being able to shift down into the smallest rear sprocket (the chain would keep jumping back to the second smallest sprocket). I had the derailleur adjusted by three different mechanics in three different shops without solving this problem. Finally a mechanic suggested that I had worn out my rear sprocket and that I should replace it. I was very surprised that it would have worn out so quickly (the problem started showing up after just a few weeks of riding and continued intermittently). Fortunately I didn't need to replace the entire cassette, it turns out you can buy just a single sprocket (although whether they will be able to get one in quickly is another matter). The mechanic reckons the replacement sprocket looks stronger than the original and so far I haven't had too many problems with the rear cassette now that the sprocket has been replaced. I'm being a bit more careful with my shifting and also now try to use some of the other gears a bit more (from years of single speed riding I tended just to sit in the hardest gear). Given the difficulty I've had in sourcing parts, I grabbed a spare sprocket when they were in stock. IMPORTANT TIP, make sure the little lever on your derailleur is switched to on, if it is off there is more slack in the chain and I think this may have contributed to this problem (only switch it off when removing the back wheel and then make sure you switch it back on again).
3) When the chain comes off the front chain ring and gets stuck between the motor and the chain ring it is a SERIOUS hassle to get it unstuck. There is just enough clearance for it to get in but not out again (at least not without damaging something). This is a major design flaw in my mind, a few mm extra clearance would have removed the issue) I've had the chain get stuck 3 times now and am wondering if there is some modification that will either prevent the chain from coming off or make it easier to get back on. The only solution I came up with in order to free the chain was to completely remove the chain ring, which is fiddly, messy and time consuming (and also risks losing small parts). This can be done on the road side armed with just an allen key but it takes me about 15-20 minutes and I end up with grease all over my hands.
Taking the chain ring off requires removing four allen bolts, taking the guard off and then the chain ring off (you don't have to remove the crank to do this). Be very careful not to lose either the 4 bolts or the 4 "nuts" (first time I did this I spent ages hunting some that had rolled away). You can then easily free the chain, then comes the much trickier part of reassembling the chain ring. I've yet to come up with a nice quick way to do this, the problem is that it is very hard to keep the "nuts" in place when putting the chain ring back in place (they tend to fall out as nothing is holding them in place until the bolt goes in). Best I've come up with is to do one at a time, rotating the chain ring around to where my fingers can just about hold the nut in place from behind, while screwing in the bolt. Maybe if I taped them in place onto the chain ring it would be easier. Also remember to put the chain guard on the right way around, it is easy to install it backwards and then your chain won't fit back on.
My mechanic had someone come in with their chain stuck on the same model and I was curious to see how they dealt with it so I stuck around. They spent 10 minutes trying to free it before resorting to brute force and some sort of tool that I don't carry with me to try and move things - so it isn't just me.
4) The integrated pannier rack looks great but I had issues with it not quite fitting my ortlieb panniers. The fix was to by the MIK rack deck:
https://www.giant-bicycles.com/nz/mik-rack-deck-2019 which solved the problem BUT I had to wait about three months for it to arrive (getting spart parts seems to be a real issue in our corner of the world)
5) My rear wheel started rubbing on the frame. Fortunately I had read about this kind of problem and as I expected the wheel was no longer sitting properly in the drop outs). I loosened off the quick release, re-adjusted the position, and tightened it back up really tight. So far the issue hasn't returned but I'll be keeping a close eye on this.
6) The display that mounts on the handle bars occasionally fogs up on the inside (presumably moisture getting in). I had this replaced under warranty but my replacement unit has the same issue. The moisture does seem to disappear after riding for a while in the sunshine but it does make it hard to read speed etc until the display defogs. Annoying but not a show stopper.
7) The handle bar grips aren't particularly good at damping out vibration and I often end up with numb/tingling hands. I didn't have this problem on my previous bike. I've upgraded to some different grips to see if this solves the issue:
https://www.giant-bicycles.com/nz/ergo-max-plus-lock-on-grips-w--bar-ends Too early to tell if this will solve the problem although I'm enjoying being able to use the bar ends. It should be noted that the controller that mounts on the handlebar is designed to slot into a particular style of giant grip (lock on ones), so your options are limited (unless you butcher a giant grip and cut a bit off so that you can still mount the controller while using a different grip.
8) Lost the screw that held the rear mudguard in place - not a biggy, just needed to take the wheel out, find a screw that fitted and replace it.
I've also had a couple of punctures so far but that's to be expected if you commute any sort of distance regularly.
Given all the issues, would I buy a Giant Quick E+ again? For me the biggest selling point was the 45km/h speed and I've yet to see anything similar on the NZ market that looks better than the Giant Quick E+. A lower maintenance, hassle free E bike with a 45km/h speed limit would be my preference but I'm not sure one exists.