I've bought from AliExpress several times over the past 3 years without any problems (Kayfun and Dvarw clones and some 21700 tube mechs that I couldn't find anywhere else). Obviously ordering from China is going to take time but the longest I've waited is about two and a half weeks so it's not been too bad.
The only thing I would advise to be wary of is a few sellers have the habit of listing items that no-one else on Aliexpress is offering that they simply don't have in stock - if you order an out of stock item they will contact you immediately and offer an alternative. Just say no to this, but don't cancel the order. AliExpress will automatically refund you after 8 days - if you cancel they will not refund for a month. Coolvape have tried this one on me twice. I avoid Coolvape.
Other than that I've had no problems, but when buying from China, patience is a virtue because it won't be fast.