Peter, we think your choice is good. DW and I bought an '07 3400 last year, new off the lot. It was a show demonstrator. After looking at several other brands, and all the floor plans that Montana had, we just kept going back to the 3400 again and again. Finally decided that was the one for us. Had it out several times for weekend trips earlier last year, then did a two week stint on the road. Absolutely loved it. The four slides and the largeness of the trailer allow us "room" to move around. Only problem we've had with ours was the shower leaking. That seems to be problematic with ALL brands, as the one we had before (SOB) before leaked as well. Seems the factory just doesn't seal well around the joints. It IS an easy fix, and since this is a "used" one, may have already been done. The only other thing that has happened was all the cabinet glass "safety liner" material delaminated, but the factory covered that under warranty. We have the fireplace, which we thoroughly enjoy. We've done some minor "mods" to ours too, including trading places (like others have done)with the recliners and the sofa. We love it, and plan to do some travelling this year, after I retire in June!
We pull ours with a GMC K3500 Duramax/Allison SINGLE rear wheels (daily driver) and have had no problems.