I have one of these.
It's all right. The biggest issues for me are the brakes that are very difficult to get adjusted right, and the lead-acid battery that dies after about a year. Also, the quality of the battery charger absolutely sucks. Other than that, the quality of the bike itself is fairly good.
This is a heavy-ass bike, by the way, it's about 70 lbs, which makes it nearly as heavy as a moped. Pedalling a moped without the gas engine is a joke. So is pedalling this thing without the electric assist. That's more or less the only way I'd recommend using this thing--don't use it solely on electric, don't use it solely with pedalling. Always use both at the same time. And don't expect to go fast at all.
It's been a nice cheap electric bike but honestly I'd have to recommend something else, either a much nicer e-bike, or just a regular bike, or a moped.