I was one of the first immigrants into H&H (Jorb and Loftar's former game), and I just felt like posting the issues with H&H that I really hope these guys don't end up dragging into Salem.
1. Massive grind. The primary trouble with H&H was that it was a massive grindfest with permadeath and open PvP enabled. This was due to the lack of skill or ability caps, which meant progression was infinite. This caused a bunch of other problems that I may talk about later.
The massive grind WAS useful for discouraging players from fighting from one another (what's the point when the risks are so massive?), but it also meant that both griefing and using alt accounts to attack your enemy were far too good as tactics. Just create a few noob characters, grind upto the murdering skills and go and slaughter enemies with your disposable characters.
2. No skill caps. This discouraged both grouping with other players and specialisation. What's the point in being specialised when you can get to a level in one skill and use your ability points in that skill in all others?
3. No diminishing returns from abilities / skills. This meant a massive divide between new players and oldbies, which is never a good thing in open PvP scenarios. Was resolved slightly with resets over maps, but that didn't really sort the problem out.
That's pretty much it. Keep in mind these are major problems that need to be resolved before this game gets even out of the design stage, though.
EDIT: I played about a year back, so everything might have changed by now.