I like the grip angle. That is a natural best fit for the human anatomy.
I decided to go with a Volquartsen trigger up grade kit in my Mk III Comp & MK IV Hunter. The stock triggers maybe ok for the so-called average shooter. I wanted better. The trigger on most new guns these days is the down side. That includes Mk pistols. My IV was worse than the III. They can be dry fired a little. A dealer should let you dry fire it. You decide.
There are lots of accessories if you like tossing money at your guns. It is mostly a lot of wasted money in my view. Except serious target grips and there the after market is just getting caught up to the IV. I do fine with stock grips. But, the Mk III comp grips are better than the Mk IV comp grips. The hunter grips are the same feel from III to IV.
It has an ambi safety that can be converted to right hand only. The detent is weak. Kind of a design flaw in my opinion. Not a problem for me, just annoying to me that Ruger engineers would mess up something so simple.
They had a recall on the Mk IV sear (and also new safety part). No problem on the new guns. An older Mk IV or any Mk IV there should be an "S" on the white safe spot. if not you can send it back or just install the VQ upgrade and dump all the suspect parts. (my opinion, only fwiw)
I like a steel frame for a steady hold. And I just like steel. For steel the choices are the Competition or the Hunter. I recommend both or either. Really the comp for nth degree shooting or the hunter for killer looks. No pun.
The target is aluminum framed. In an aluminum gun, I would expect something like a tapered 5 inch barrel to compliment the light weight frame. I dont see a light frame with a heavy barrel. They sell like hot cakes, so what do I know. You can save a few bucks and get a fine pistol, I guess.
The Mk IV is a nice upgrade over the Mk III with easy take down and they removed the problematic Loaded Chamber Indicator.
If you mount a scope and test shoot off a good rest, 1/2 inch 5 shots groups at 25 yards are possible. I got that with a Mk III Competition and would expect the IV could do the same. I would have to pull my file on the Mark IV Hunter. I think it was close to that, maybe not quite as good. I think an inch should be expected with any Mk xxx and right ammo. The Comps might have a slight accuracy edge for reasons unknown. Without a good scope (4x optical scope) I doubt anyone could ever know.