What would you propose for a horizontal progression system to replace what we have?

Personally I don't really have a problem with the vertical system. Sure I'll take breaks from it now and then, but in generally I like gearing up and getting items, and wouldn't neccisarily want a pair of boots that are going to be better than anything I get for a couple years. I never played XI or any MMO with a horizontal system and nobody's ever really explained it in a way that makes sense to me.