I had an Armalite AR-7 (i.e. the Henry Survival) as well as a Papoose, and I much preferred the Marlin. More solid feel, much better accuracy, nicer gun all around. Trigger wasn't great, but much better than the AR-7. I also found that the Papoose returned to zero fairly well after disassembly/re-assembly.
The Papoose has a nice padded case, but you might want something with a bit more protection, depending on exactly how you will be stowing or lashing it on your ATV. I used mine sometimes with a very small scope ("Beeman Short Scope") and more often with a Williams' peep sight mounted on the dovetail. Nice little gun.
John