A couple of years ago, I sold my Otter T600 and went with the Clam Nanook Full Thermal. Not having a quad or snowmobile the Otter kicked my butt every time I took it out, not to mention loading it into my truck. I would have to agree with jbuss79, the Clam Nanook is very manageable for one person, but yet big enough for 2 people. If it's an option, I would strongly consider the Full Thermal, it ads a little weight and is a little bit more from a price standpoint, but definitely worth it.

Good luck in your search.