You can't shoot an MG like that, you just can't. For a start the thing is terrifically heavy, next the recoil should cause it to ride up like a mule on speed.
The simple fact is that at the moment the reduced recoil on a good amount of the weapons, the lack of sway and the robotic arms that allows pin-point aiming in a nansecond ruins any sense of realism.
As for the MG in relation to this thread (i.e. the title) the MG should have a greated effect. I've said on various occassions, perhaps maybe even on this thread, that suppression should be significantly greater. This is generally a marriage of the sound, the effect (dust and such), the aesthetic effect it has on screen with the player and finally an effect on how the player behaves. The latter is usually shown as shaking, with an inability to aim properly. Without this, the MG's purpose (to supress) is ultimately destroyed.
Some say the recoil is off but I feel that's about right when you're resting it on a bipod, a bipod isn't a magical gizmo that automatically makes a machinegun an automatic sniper rife.
The rest of the MG mechanics, such as the riflemen carrying ammo and the really nice set-up feature really do give it brownie points. But they're completely out weighed by the points i've stated previously.
On a side note, the upgrades for the MG34 are awfully in accurate, 200 round belt fed? Sweet Jesus you're practically asking the players to go Rambo. Perhaps in the future (and with the removal of the dual mag) the MGs could work in specific squads (three man teams) which, when stationary and with at least one other member of that team the MG can switch to the larger belt. This would be a very nice gameplay mechanic as it means an MG team can lockdown an area with the force an MG could do in the war. When against squads of riflemen they are meat grinders.
Apologies for typos and what not but I can't be bothered to spell check this one. Peace.