I played two games of HoN and stopped playing for a few reasons. Mostly because it was difficult to figure out what to do and what to buy because the game didn't do much to actually explain anything to newbies, but also because I got the feeling that it was a game where there's a lot of pressure from teammates to not screw up, and I don't really like playing games where there's that much pressure. I like multiplayer games but I don't like it when they get really really competitive; I'm more of a "for fun" kind of guy, and DotA-type games are more of the former.
This I might play if the barrier to entry is lower and the community isn't hopelessly hostile, but it's also of interest to me because of the Steamworks improvements.