I've said this a few times here, but applying a simple filter of 98% feedback or so and at least 25 feedbacks will avoid 99% of the issues. You can also look at

I've said this a few times here, but applying a simple filter of 98% feedback or so and at least 25 feedbacks will avoid 99% of the issues. You can also look at the expected shipping speed. There are plenty of good, large sellers, and they didn't get that way by skimping on quality. You don't need to take a chance on smaller sellers if you don't want to. (Also, many sellers use FBA which avoids most of the issues, the only concern there is really product quality, which again is something you don't need to worry too much about if it's an experienced seller. Commingling can cause problems, but it's very rare, if Amazon saw a significant number of problems from it they'd have stopped the program.)