Late to the party here, but I just saw the Momentum 351 at the RV Show in Tampa. Having had several garage-less toy haulers in the past, the 11' also concerns me. However, I really thought the floor plan was awesome. If you can eek out 2 more feet, the 381 has the 15' garage. I've been thinking about going the MH and trailer route, in an effort to keep things smaller, but this trailer has me thinking. Unfortunately, there are some pretty tough reviews about Momentum online. I was thinking they might be a higher end operation, but perhaps not.
2006 Chevy 2500HD 8.1 4x4 CCSB (sold)
2012 Eclipse Stellar 28SBG, Spring Over Axle (Sold)