I have a P345 and think it is a fabulous weapon. I did have a few very minor issues with mine at first. The magazines did not drop out of the gun when the mag release was pressed. As a matter of fact, I had to literally pull the suckers out with force. I don't currently compete in IPSC, so this wasn't a big deal for me. Also, I find the 3 dot white sights are quite small (I'll assume for CC) and I have a little bit of a hard time focusing on them. The sights dots were also poorly painted (some black is visible at the top of all the dots). The magazines also ONLY hold 8 rounds, which might be a hindrance if you are shooting IPSC and get a dud round or two. The Double action pull is INSANELY LONG. The first time I shoot the gun in double action, I almost thought that I was at the limit of the trigger stroke when all of a sudden ---BANG---. It totally caught me off guard. One more negative. There was a small little plastic bit that was extended from the gun on the right hand side of the grip when I first bought it. Not knowing any better, I went to the range and put 200 rounds through it this way. To this day, I don't know what the plastic bit does or why it was extended in the first place, but I don know that as soon as I pushed it back into the grip, the magazine release started to work flawlessly. The mags now drop without issue.
Positives. First of all cost, I like the $600ish price tag. I'm not a big .45 shooter because of the cost of the ammo, but I did want a .45. The Ruger 345 fit the bill as being a cheap little .45 that I didn't feel obligated to shoot every weekend because I just dropped over a grand on the gun itself.
Second, the size. This is a small gun. The barrel is 110mm (I think) and its the perfect size for my hand. Also, it is incredibly small. I'm a big fan of small handguns and not being 12(6) licensed, I wanted the smallest size - biggest caliber I could get. The Ruger fits that perfectly.
The single action pull is dramatically light, maybe 4-5 pounds. Compared to the double action pull, its a hair trigger. I like it and it works well for snappy follow up shots.
Overall, I like the 345. I'm not sure about Semi-wadcutter bullets feeding but I will say that everything I've put through it so far has worked fine.
Also, the 3" groupings at 50 yards, for myself at least, is an urban myth. I'm lucky if I can hit the TARGET at 50 yards, never mind keep everything at less than 3". This I will attribute to my personal level of skill and my approach to shooting. I don't slow shoot, I bust caps like my life depends on it.
One more thing I'll mention, disassembly is a pain in the ass the first time. I spent about an hour reading the manual trying to figure it out. After I got it apart the first time, every subsequent time has been a breeze.
Good luck.