Re: Ruger 10/22 or Marlin 925/XT-22
If the question was was changed to: AR15 or Rem700, both in 223 would you be able to answer it yourself. The question you pose is very similar. A 10/22 will be semi auto with a ton of options to upgrade later on. The accuracy will not as good as the bolt gun (haters, hate away) but it will be good enough for plinking and varmint hunting. The Marlin will give you better out of the box accuracy but you'll be limited to what you can do with it after the fact. The trigger can be made to be much better than the 10/22 without the expense of a 200 dollar trigger group. I've done plenty of 10/22 builds over the years and you can get them good but your going to have alot invested in it if shooting for accuracy.
For me, when walking out the door with a 22lr it's going to be one of my Marlins.
As far as cons to the rifles, there really aren't any. The 10/22 is tried and true. The XT-22 series is the same as the 25 series which are also tried and true with a new trigger. I don't much care for the accutrigger style that the new marlin has but it wouldn't be a deal breaker and some guys like them. Of course last I saw, the base model 10/22's have a plastic trigger group now.