FT have been wonderful in my experience. Stuff ships out very fast, often same day if I order early enough in the Chinese AM. I've only once had a product go into "restocking" and miss its ETA, out of god knows how many products I've ordered in over a dozen orders. And ironically I cancelled the product quickly to let the other items ship and then added it to a new order, only to see it was now in stock only a couple of hours later. It must have been a warehouse mistake, thinking it hadn't arrived when it had. So really I've never had any product delayed beyond the ETA.
And I've had all my tickets answered within 24 hours, which is their stated service level. The 24 hour response is sometimes annoying, eg when I wanted them to change a product that was out of stock for an in-stock item, so it could ship quicker, and it took them 24 hours to respond and then another 24 hours to do it, by which time the other product was now in stock. But those are isolated incidents, and to be fair they warn up front how long these things will take. Given they must be doing 10s of thousands of orders a day, the same level of quick response can't be expected as smaller vendors.
Focal and 3FVape have also both been good, especially Focal. And being much smaller, they do provide that more personal, faster response - you can even talk to Focal's Doris, their number one customer service person, on Skype.
GB I've only heard bad things about so I've never used them. Nor have I used AngelCigs, about whom I've heard almost nothing - neither positive nor negative.