Anon here with buying tips and overall review. First of all, download the app and do all your buying through it and not the site. The search is better, you can see all the reviews and customer pictures without searching for them, and it uses a secure server for CC processing.
When buying bootlegs look for the star count and 'orders' to next to it on the right. The more orders the store has has the safer it is to assume you'll get your product and get it on time. You'll have your pick of different prices for the same item as multiple stores sell the same KO or bootleg. Make sure you check the customer pictures to see what the item -really- looks like in hand. Case in point, the movie Ghost Rider figures that's so popular there. The stock pics make it look incredible but the actual pics and reviews show it to have a very soft sculpt and piss poor paint apps.
You'll be treated to a discount when you buy from the app and get coupons for your next orders. Most items are free shipping and the bootleg/oversized Transformers I've ordered took 2 weeks to arrive. I haven't had any cc problems in the 3 years I've been using the site and have ordered Metal Slug kits, Star wars black bootlegs, transformers, figma, fuguarts, all bootleg or oversized/KO.
You may need to search for different terms like 'transformation robot' and 'tracer figure' instead of figma. Wei Jiang oversized TFs are some of the most popular sold toys there and you can find orders in the thousands for stores that carry them. Always check the slider that display 'customers also bought' because it can lead you to better stores with more orders or faster shipping.
I haven't had to use their dispute option but have contacted seller stores before and have gotten fast responses. Most stores will send you replacement parts or items without question rather than go through the hassle of a dispute or lowered star ratings. In this way Ali Express is more on the buyer side than eBay.