I purchase online.
I think the best answer is try it out and the worst that can happen is you receive something that looks completely janky but works. There is a fasttech thread somewhere around here that people post what they get from fasttech and the quality. I'm not sure, I just did a search and cannot find the thread. However, when it comes to the products that fasttech sells, I'm sure we'd hear about it if they scammed or their products were not up to standard.
I recently made a purchase with fasttech and will be receiving it soon (hopefully.) I can update you on what I get and how it looks, but beyond that, you're probably better off trying it out and seeing if you like it.