I have three Rugers, two Mark iii's", a Target Model and a Competition Target model; also a Mark ii, Government Target Model. Have never tried the 22/45, so I don't have an opinion.
I shoot the Mark iii Target model, which has the shortest barrel, at least as well as I shoot the others; it is just as accurate. The Mark iii Competition Target model has a slab side barrel which shows me no discernible performance from the bull barrel on the Mark ii Government Model.
I shoot the two Mark iii's using telescopes, if I'm having a good day, 1/2 groups at 25 yards are possible. I started out using cheap red dots on them; the results weren't good, so I went to the scopes. The Target seems to be the better balanced of the Mark iii's.
The Mark ii isn't drilled and tapped, so I shoot it with its iron sights. I can't get a 1/2 group at 25 yards with it. It shoots a nice tight group, but I can't see well enough at 25 yards to do the gun justice.
The Target Model was best out of the box, but I felt it needed a smoother action and installed a Volquartsen kit of hammer, sear, trigger and bits. It is ultra smooth and light.
The Competition Target model had the worst trigger I've ever pulled on a new gun. I went to the Volquartsen kit after shooting about a half box of ammo thru it. It's very nice now, not as smooth as the Target; but OK. AND, the rear adjustable sight fell off when I took the gun out of the box. It didn't bother me because I intended to use red dot, or scope; but, I'm going to send it to customer service. I may decide to try iron sights shooting with all three to compare them.
The Government Target model was purchased used. It looked NIB; had a beautiful trigger pull, but wouldn't extract/eject about half the time. When trying to cure the ejection/extraction problem I disassembled and cleaned the gun. It came apart easier than any other Ruger I've ever disassembled, hands only, no tools needed . It doesn't have a tool mark on it, but surely someone has taken it apart before. It was filthy! The worst I've ever seen. Cleaned everything, check extractor and ejector, looked OK. Put together: the trigger pull is lighter but feels gritty; the crud must have helped. The cleaning, etc. made it clear the extractor is the likely problem. I guess Volquartsen will get some more business from me.
I've had really good results shooting a Witness Elite Limited 9mm using a Burris Fast#? red dot at 25 yards, keeping all 10 rounds in a 5" target with small groups of two and three in 2" groups. Better results shooting a STI Match Master 9mm using a CMore red dot; kept 10 rounds in the 2" ring, the other five in the 5" target. I've used the Burris on a S&W Model 41 for almost two years. At 25 yards, it will shoot a 1" group, on a good day m/b a little tighter.
The Burris is a bit fuzzy at 25 yards, with my vision, but is almost perfect at 15 yards, perfect at 10 yards. The CMore is perfect for my vision at all distances.
the mark3 competition model 10112 might be your choice close to a 7" barrel, slab sided. sweet. In the 22/45, there are any number of 22/45 models except for a few special editions with fluted barrels or the availability to change out grip panels all are pretty much the same. The ones with the fluted or slab sided barrels weight a few ounces less and are more expensive. but the barrel internally is the same. I would get one at a little lower cost and invest in some Volquartsen internals. Mine is the base model with a volquartsen sear, a tandemkross bushing, and slingshot mod. It has over 3500 rounds now and has never had any ftf or fte issues at all. It is a tackdriver out to 25 yards and is super fun to shoot.
Being the cheapskate I am, I bought a 22/45 Target with bull barrel. It is accurate, reliable and fun to shoot. However, it ended up costing me more than the initial cost of under $300. It caused me to want a real 1911. Still being a cheapskate, I bought a RIA 1911 Tactical in 9mm. The 22/45 and 1911 feel, aim and shoot exactly the same but the 1911 has moderate recoil. It makes practice more affordable with the 22/45 and it translates to the 1911 well. My 22/45 cost me about $800 considering I would not have bought a 1911 if I had not bought it in the first place. I now wonder why I waited so long to buy either. They are my 2 favorite handguns of the 7 I have.