Great choice...I got mine last year from Wolverine (who had a nice selection of HK products last time I looked!), grab some extra mags whenever you can as well!!!
I have the full sized HK45, love it. Better grip then the C model and better looks IMO. Its has the grip angle, controls layout and slimness of the 1911 but a better standard capacity at 10+1. Then add the durability and style from the USP but with a "standard" 1913 light rail, finger groves (love or hate for some people) along with a slightly longer sight radius, an o-ring on the barrel for a tighter lock up and a ambidextrous magazine and slide release.
PS.
Holsters are also easier to get for the full sized model. I have a Safari Land 6004 (drop leg) for mine and its a great holster, can be easily converted for a mid ride, belt or vest wear as well.
Not sure if your used to HKs or not but they shoot with the "cover" method...not the 6 o'clock hold that is more common....its a very very accurate gun if you know what your doing. Using standard 230gr ball its no challenge for me to hit empty 12g hulls at 10 yards or 2L pop bottles at 50 yards and with the recoil reduction system it has it makes it feel like a 9mm so making double taps is easy and effective.
HK sight method is on the far right.
Mag release is in the trigger guard and of a larger and "better" size then the ones on the USP line IMO but it may take a range trip or two to get used to it. It has now become my preferred way to drop a mag compared to the more popular button magazine release and is fast and effective to hit with either your thumb or index finger.
It is an expensive gun at $1399.99 plus taxes and possibly shipping and magazines at $85.00/each kinda suck but you get your moneys worth for sure and anything HK holds their value well. I spent well over a year before I made my decision on what .45 Auto I wanted and read may reviews and personally tried out many models in the caliber...the USP Tactical 45 (which I do own still), 1911s, SIG 220s, Glock 21s, M&P 45s and so on. The HK45 won hands down...in all departments but the price tag.
Great test done on the HK45 if your interested in it...
http://pistol-training.com/archives/4027
Very impressive results!!!
Enjoy your HK!!!
- J