I bought an HK45c in late December last year. I haven't and seriously doubt I ever will regret the decision to do so.
Great shooter and also light in terms of weight comparably to classic style full metal frame 45's.
Haven't shot the HK45 but I have shot a full size P30 which ran 40. And while it shares the same ergo grip as the full size HK45, I actually like the clean straightforward grip design the HK45c offers. I did get a Hogue grip but found I like it better without.
I run Remington Golden Saber Black Belt in 230gr as defensive ammo. Have a couple boxes of Black Belt 185+p simply becuz I wanted to feel how it ran.... All I can say is that HK has done an excellent job with the way they engineered these firearms.
Felt recoil even with +p in 45 didn't kick as much as I expected. Snappy no doubt. But controllable once U get used to it.
I would imagine the full size HK45 would perhaps do just as well if not better.
Overall, IMO, U can't go wrong with either. BTW I carry my HK45c daily concealed with no issues. I use a Tagua Cannon TX BH3 OWB holster.