My AliExpress experience was quite so-so, with average certainly worse than Ebay. When I bought a bike part, the seller never sent anything. After I started complaining, they stated that they ran out of stock. (In my opinion thay never planned to supply - the low price was a bait.) Then they said that they would only refund me if I started a dispute. I got my money back, but it was an unpleasant experience. Next I bought an electronic enclosure and the two halves did not fit together well. I wrote a review about it and then the supplier contacted me, apologized and supplied another set that worked well together.