It depends on the kinds of things you order and how attuned you are to the games they play. If it's all name brand stuff and you are careful to actually order from Amazon and not a store hosted by Amazon it's not bad (although there are a lot of counterfeit goods on the site, in mixed inventory so it can come directly from Amazon even if it was stocked by some other store).

If you're getting commodity stuff from the cheapest vendor, good luck. There's lots of stuff put in there by Chinese shops that's garbage quality, mislabeled, a miniature model of the real thing, etc.