Not a big fan of the plastic build-quality of the trezor and the crappy USB cable broke very fast on me too, but otherwise, best-behaving and trusted wallet so far, I may have to get another one - I do hope they improve the quality, I would like it to be metal instead of plastic! 
I thought that trezor is made from some high grade quality plastic, like thinkpad T/X laptops or guns and not from some low-cost one..I'm potentially interested to buy one, but build quality is quite important to me..can you please share little bit more?
I suppose the plastic is above normal quality, but it doesn't feel like it's anything too special. Like I said, I would prefer some type of metal case, but they don't make one. Overall though, I do think it's safe and very easy to use.