^--the first is a brand new seller out of China (well, at least a new Ebay account). It looks like it is a variant of multiple accounts or multiple previous accounts due to negative feedback, hence the -8 appended to their username. Lots of Chinese resellers do this. They'll close their old account and make a new one with the same user name and a -2, -3, -4, etc.
2nd one is an experienced seller, so read all negative feedback. They try to get negative feedback removed, so take all negative feedback seriously.
I usually still purchase from some sellers like that and just gamble that I'll get something that works if it absolutely cannot be found elsewhere. Then when it doesn't work, I leave negative feedback stating that the product is counterfeit if I can prove it which is usually pretty easy -- they'll refund you almost immediately.