I own the Marauder/Nomad, and bought a Mossberg for my buddies birthday, after shooting thousands of rounds out of both, I can honestly say that I would prefer.......
The Marauder. Well, this is a gun design that always tickled my fancy and just filled that hole in my heart. I have the "collectors" edition Marauder stock, which has now been renamed to Nomad due to some copyright issuess
Pros:
-Its a 10/22, lots of aftermarket parts and pieces that can be added just internally to make it a sweet rifle
-The little bit more weight is more to my liking
-more solidly put together
-my mags work just as effectively as my Butler Creek mags (however they did need a break in period)
-Folding stock (just fits in things better for tactical hunting trips

)
Cons:
-Mags can be tricky, but should have been fixed mostly with the gen 2 mags
-Can be difficult for some to assemble with not always exact flashing (a knife, a beer and 30 minutes was all it took me to get mine done)
-The rail is rather high to mount an optic on, but not as high as the mossberg
-Chunky front sight, but less so then the mossberg
-Becomes restricted if you install a shorter barrel and DON'T pin the folding stock
-Price, you need to buy the kit, and a 10/22
The Mossberg is fun, I will grant you that. However the things I noticed were enough to stop me from buying one. But I will start with the Pros.
Pros:
-PRICE! at roughly 300 bucks you have a complete, ready to go, tactical rifle.
-fairly (in my experience) reliable internals.
-Design (love that M-16, M-4 look with the carry handle)
-very easy to sight in, and be plinking away at cans from 10-40y
Cons:
-THICK iron sights make the mid to long range precision (50y and beyond) a little bit more tricky
-The optic mounting solution (on top the carry handle) is rather high, and really messes up a zero once you try to shoot further or closer
- Felt like it was a cheep toy I would buy at a dollar store
- The high cap mags work well, but are just an awkward and aesthetically annoyed me having that long "stick" out the top. I was afraid to break it at times
-little to no aftermarket internal performance parts
Both are good working guns, but with those observation's, you see which I would go for every time. I hope this helps you out, and either way you should be happy with whatever you decide.
Last note: Yes the SR-22 is a bit more expensive, but when you go that route and get everything you want installed it is hard to beat that look and keep it non-restricted.
Mine