My mkII is more accurate than my sr22, but just by a little.
I had the sr22 out today and just pumped as many as I had time for - probably several hundred rounds. Great little gun. No problems. There was one dud round out of all that and thats what you get sometimes with cheap bulk ammo but gun was fine.
BTW, if you put the pinky extension and the large size grips on it like I did, it fits a large hand very well.
I would get the sr22 cause it is also very easy to take down unlike the mkII.
I might also get a Baretta u22 cause I have a red dot that would fit on it and look pretty futuristic and I am unable to mount it on these two guns.