I've had the FLX Roadster for 2 years, straight out of kickstarter. At first I loved it, as it was my first e-bike. It is a true life changer and the best mode of transportation in many cities! It "flattens" hills, which is an incredible feeling. You get pretty quickly to 20 miles/h, which is a great cruising speed. My top speed (downhill) was ~35 mph; beyond that, it's too dangerous anyway. It's also nice to be able to take the battery out and recharge it elsewhere.
Sadly, the bike is extremely poorly built:
1. They claim the battery can go for 30 miles or more. Mine gets weak after 15 and dies at 20 miles, in ideal conditions (I would say 15 miles max in winter).
2. This is the flimsiest bike I've ever had. So many screws, nuts and bolts have popped at least once. My 2 fenders are broken (one is because the bike fell while standing).
3. To top it up, the motor died after 14 months of use.... I emailed them right before it broke. They emailed back and forth to tell me that they were about to get spare parts in a shipment. After 6 weeks, I finally got a replacement, and had to pay $75 for a known issue! Four months after changing the motor (it was a 4h project...), I can sense that there is something wrong again when I pedal... :(
4. They sent a bike seat with the wrong "minimum depth" marking on it, so of course, the frame cracked... They want $280 to ship me a replacement frame, for THEIR mistake. They also offer to cover the welding cost, but the worst part about it is that no bike shops want to service it anymore (because of liability issues). So I'm on my own...
5. They are extremely slow at handling problems. Both times (for the motor and the frame), it took ~20 emails (mostly me asking "can you please reply?") and 6 weeks!
6. More minor details; I don't find the "user interface" of the control panel very intuitive or efficient. For example, you need to set motor speed every time! The gears were never really aligned, despite a professional tuneup after 200 miles. It derails quite easily over bumps.
In short: Don't buy this bike, it's too flimsy and too much work. There are great alternatives!