I've ordered loads of stuff from FastTech. You just can't be in a hurry. I've always received my items within 3 weeks, +/- a couple days, of it shipping.
The only issue i've ever had is ordering items that were not in stock. FastTech posts ETAs or Estimated Time of Arrival. The key word being "Estimated". FT says these ETAs are based on what their suppliers tell them, and they are often inaccurate. I've had items with a 5+ day ETA be ready to ship in a day or two. I've also had items with a 3-5 day ETA pushed back over 15 days. It is pretty easy to cancel items that are holding up an order.
I've had to use their warranty exactly one time and it went as smooth as could be expected. An RTA that I ordered arrived with broken glass tank. FT sells replacement glass and they very well could have offered me that, but they offered to refund the cost of the RTA, or replace it entirely. So for the cost of a new piece of glass for the one that broke, I have a second fully functional unit.
I have found that when dealing with overseas firms, where English is a second language or translation software might be used, clear, concise, and simple statements are best. It also helps to use familiar terms. E.g. FT uses "DOA" or "Dead on Arrival" to describe items that are unusable from the start, as a part of their warranty policy. When I submitted my ticket I simply used the same terms that they use. "The item arrived DOA. It cannot be used because the glass is broken." No argument, no confusion. Just a "we're sorry about that, would you like a refund or replacement?"
I also think that how FT's forum is structured is great. "Discussions" link to the exact item in question, so if you have a problem with an item you can identify exactly which item it is, and get input from others who have purchased the same thing. It's also helpful when looking at a potential purchase to see what other people have to say about it, beyond just looking at the reviews.
Yes, communication can take a few days. Yes, shipping can take a while, but overall it's one of my favorite companies to shop with.