I find Pak43s to be very useful if I'm struggling with map control because of PPSh conscript spam. None of the PPSh commanders also has IL-2 Precision Strike. On small maps you can usually cover at least 1 VP with the Pak43, which will buy you time. And Ostwind or Command Tank can roll around under the cover of the Pak43, giving you a nice safe zone from which to make your attacks.
If you use Joint Operations you can make a howitzer, too, which can force your opponent to do things he might not want to do (build a howitzer, get katyushas, base rush). Joint Operations also gives you Recon Overflight, which you should spam like crazy to get the most out of your Pak43.
(You might want to refer to the commander tool:
http://www.coh2.org/topic/14031/commander-tool)
G43s are also good against the PPSh blob. Suppress with MG42s and focus fire with the G43s on any squad that doesn't flop down on its belly. Two squads of double vet grenadiers with G43s will shred a conscript squad in seconds. Adding an LMG helps too
