Aliexpress is safer than eBay, the refund is much easier, and take a long time to expire and can be extended, I use frequently and never lose a cent.
Yeah. From a sales POV, I've had better experience with Aliexpress overall than eBay as well.
Now as far as products and sellers go, it's pretty much the same. You're still completely on your own. There's good stuff to be found, and really crappy stuff, counterfeits, etc. Usually the pricing is a good indicator of a given product having a chance of being legit or not...
Regarding pricing, don't let yourself get fooled. At first you may be tempted to think that yeah, this item is a bargain, but hey, it's normal, it's direct from China, and you know, they are so much cheaper...unfortunately, the cheap stuff, even from China, is often crap. Legit and good products on Aliexpress (and there are) are not necessarily that cheap.