It really depends on how you going to ride the ebike. I just purchased two Radrovers in Sept/16 for the wife and I. The wife couldn't keep up with me on our regular bikes. The +5000 ft and hilly terrain was starting to kick both of our butts. I also wanted more flexibility riding the 4X as many dirt trails and have the option to commute to work the 13 mile round-trip.
Also depends if the other bike is a Class I (PAS, 20 mph), II PAS+throttle, 20 mph) or III (PAS, helmet, 28 mph, not allowed on bike only paths). Some states have restrictions on class III on what bike trails they can ride while Class I & II can go anywhere a regular bike can go. I don't know how any local agency can enforce the class restriction unless you crash into another bike at +28 mph on a bike trail.
The Radcity weights about the same as the Radrover. It might be a pain if you deck it out with a rack+bag and you have to lift the bike up/down stairs or place on bus bike rack. I like having the Class II PAS+throttle because you can use the throttle to walk your bike up inclines/ramps when needed with zero effort. The throttle comes in handy if you need extra power for a moment and you don't want to hassle with adjusting gears and/or PAS levels (crossing streets, short inclines, riding over obstacles that might catch the pedals, tight corner turns, etc...).
A plus for the Radcity is it really come complete with fenders, front/rear lights, LCD, rear rack, PAS 0-5, full power throttle, 2 USB port on battery pack and LCD screen, and 1 year warranty.
I imagine the gearing is about the same for the Radcity and Radrover (limited to around 20-22 mph in 7th gear if you are peddling like mad). The 750w hub motor is plenty powerful enough to keep me squarely in the 19-21 mph range at PAS 5 with power levels between 200-600 watts (depends if there are slight inclines and declines). I'm 290-300 lbs with cold weather gear and commuter backpack full of work cloths and lunch and ebike+rack+saddle bags+accessories+ more riding gear around 80-85lbs. The 750 watt motor get me quickly up to speed and maintains me there on the 20-25 minute ride home.
I did take my Radrover on an endurance run of 3 hrs and 36 miles at PAS 3 averaging 12-14 mph on mostly level terrain. My legs gave out before the battery; which, still had one solid bar of +20% charge.
Another thing to think about is the ride gets pretty rough on imperfect asphalt on a bike at +20 mph. My 4" fat tires and Suntour SP12 NCX help smooth out the ride a little bit. I'm still doing a lot of dodging and weaving to avoid normal bumps in the road that go unnoticed in a car. A fatter tire does help with that.