G43s are awesome. They allow you to play ostheer more aggressively than with LMG42s.
Check out this replay.
Exactly what Luvnest said. They allow you to be more mobile and not have to stop to get that deadly DPS. Heck, I have had Soviet opponents run at me with a shock squad and then realise just how deadly G43s are!
interrogation is a big big deal.
Again, a fine point being made here. Interrogation is great, especially vs USF. You've just have a big battle, the forces have retreated and interrogation could provide intel about where his forward retreat point is, drop a flame bomb on him from your mortar HT and GG. And even if that kind of thing doesn't happen, it can provide you with a vital look into his FOW. Just knowing that point XYZ is undefended is worthwhile enough IMO.