I am registered on Ewaey.com (odd name I know). I got in just in time to get a free lifetime membership (no fees ever) for just $1. I was going to start listing there but there seems to be very little traffic. A local guy that sells car parts had moved his listings there and has received no bids or questions in at least a couple months. I also checked out other ebay alternatives and there's also FAR fewer items and bidders than on ebay. I know, I know, but ebay is bad about this and that, yadda, yadda.
I have just started to sell on ebay semi-full time. I do agree the fees and no negative fb for buyers is silly. I don't understand it, even if they try to explain it. Some people say it will make sellers work even harder to please and keep away scam artists. I don't know but it seemed to work well. Even still, I feel the good outweighs the bad.
My feeling about all the ebay alternatives is they're, like Jeff said, nothing compared to ebay. There's little to no traffic on 98% of them. I wanted to see what items were being sold in "Home Audio" on Ewaey just recently. Out of the entire category only three items (yes, just 3) popped up. That is absurd if you ask me and just shows where the buyers and sellers really are and will stay regardless of the higher ups foolish decisions.
Also, like someone mentioned on another forum, some of these people are probably making good money just starting these websites. Like if they say free lifetime membership for the first 5000 registrars, with a one time $1 fee, they just made $5k and they can call it quits right there. Again, I'm not experienced enough to talk about this in depth, but these are my thoughts. Take them as you will.