I decided to retire my Colt Series 70 1911 and I got the HK45C to replace it. I really like the 45C, a lot. Shoots everything, no hiccups, very reliable. I prefer the DA/SA mode, especially when carrying. I shot some IDPA with the 45C and did pretty well, even with the long hard first-shot DA pull. My DA pull is definitely not gritty and I found there was no shot placement difference between the first (DA) shot and the second (SA) shot.
I also own two Walthers, the PPQ and the P99. I used to always carry the PPQ, but now I carry the P99 and occasionally the 45C.
About the ONLY thing I do not like about a stock 45C is the same thing I dislike about all polymer pistols: the stocks (a.k.a. grips) are just too slippery for me. So, on all my polymer pistols I have installed grip tape. I used to use Talon grips, but now I make my own using GT-5000 tape from guntape.com.