Short list of known problems, pricey, Trek, Cannondale, Gazelle, Reiss & mueller, Orbea. Lots of people like their Specialized & Giant, but they have more problems reported on the brand threads than Trek.
Nearly all ebikes now have the flammable LiIon battery. Look for watthours greater than miles*18 for range.
SRAM makes a quality shifter now too. I've had a 7 speed shimano rear axle unscrew the race & drop the balls on the road. Cheap unreliable design for cheap kiddie bikes. The 8 speed shimano I ride now has gone 6500 trouble free miles. 8 speed chain lasted 5000 miles with a hubmotor. Expect less miles from 9 or up speed chain, and 1/2 or 1/4 the life of chain on a mid-drive. Belts are good for maybe 10000 miles but can be kinked by impact, and make it more difficult to change the tube after a flat.
You can't ride a geared hub motor up mountains >1000' in an hour, they overheat. Otherwise, better chain life, inexpensive, and not as likely to drag unpowered as mid drive. Mid drive with torque sense is more controllable over rocks etc on real mountain biking. Torque sense can now be bought with a hub motor.
I suspect cheap air suspensions myself. If the seals leak, will there be a replacement available. If the bike has a standard fork it can be changed. I ride hard suspension, but not much off road.
There are plenty of dealers in Vancouver. If you buy from one, you are no longer the repair department. Calling a phone number about some flaky electric problem is not a pleasurable experience. Then you have to put the part on yourself. Most dealers won't work on an electric bike they don't have a franchise for.
I handled the problem by throwing 2 batteries away and buying something else, but then I didn't ride electrically for 8 months.
Lots of chatter now about hydraulic disk brakes. If you race downhill and wear the pads in one or two runs, the self-adjustment feature is important. I have cable pull brakes, the pads last 4000 miles and changing them took 30 minutes with an allen wrench & a plier. 140 mm cable pull brake stops me fine at 330 lb gross weight on 15% downgrades. I adjust the pad about every 1000 miles. Takes 5 minutes with an allen wrench except for taking the pannier off & replacing.
Happy shopping.