Thanks to all that posted about this, I'm still interested to hear more, but I thought I would share my experience so far:
I talked to my first contact at Afternic. He called me back and apologized for not having called me back the day I first called them. I explained that I had contacted Pete from here on NP and he had a rep call me. But I was able to ask him some more questions that helped make my decision to join them. I asked about having two accounts, one of each type, but after I paid the $20 fee and joined, I saw that you can select a different listing type, basic or expanded for each domain. Afternic, why didn't you tell me I could do that...?

So most of the domains I added are basic, with one that I think will sell for a lot under the expanded option.
When adding domains to sites like this I KNOW you have to take some time and make nice listings, otherwise it's not going to work very well. So I imported about 12 domains and used default settings for prices and then edited each one to assign them categories and adjust the prices up and down for each domain. I also created a description for each one. This should help the domains to be found, and also to "sell" them to a potential buyer. Most of the prices may be somewhat low, but I would like to get some quick sales, even if I miss out on making some money for now.
Anyway, the process is pretty easy, and while I don't like to pay a fee for domains that are sold on comission, $20 is a small investment if it works.
To be honest, one reason I didn't jump right in is that I have never liked BuyDomains. Their prices always seemed like a ripoff, but that was before I became a domainer...! Some of the sales reps seemed pretty pushy also, and I don't like that and don't really want my domains sold that way, but business is business... So far my experience with Afernic has been quite good so we'll see how it goes.
By the way, I don't think I mentioned why I decided to try them. I've been getting updates from Domain Name News via email, and about once a week they list all the latest sales from Afternic. When I looked over the domains and the sales prices, the thing that struck me was that I have been buying domains of the same quality for the past 3-4 months, and some of them are much better that what was being sold (IMO). So I'm hoping this may be a way for me to selling all the domains that I keep finding that are maybe not so good for parking, but would be great if developed.