Oakiris,
I don't have Raul's knowledge about the history of tonearms, but from what I've seen and heard I agree with him.
I've not used a Moerch but I have used a Graham 2.2. IMO a new one is one of the most overpriced components around, particularly since you have to buy a separate phono cable. A new 2.2 + IC-70 actually lists for the same as my Tri-Planar. Some may disagree but IMO that amounts to a bad joke. The Graham may look cleaner and tidier, the paint job is better, but its superiority ends there.
Used Graham 2.x arms are now plentiful, thanks to the introduction of the Phantom, so you might bag one for cheap. However, if I had to choose between a 2.2 and a DP-6 with no chance to learn any more, I'd choose a DP-6. It's probably better, like Raul says, but even if it's just equal it's also less expensive, more flexible as to cartridges and much prettier!
Salectric's JMW-10/DP-6 comparison was interesting. "Richness" and "opacity" are not desirable traits in a component. "Rich" sounds nice at first, but it's really a polite word for "colored". That can get tiring before too long, and it's a pretty fair description of the Graham's sound too.