I have not been in one but have several friends that have. First off they make (or made?) two sizes. The original was bigger and now they make a smaller one (not sure if they still make both or just downsized - I think they make 2 sizes....) anyways - one buddy rowed the bigger one and he liked it, but it was big, really high sides - said it felt a little ungainly but it floated high and rowed OK but not great. He rows hard boats exclusively, so he's comparing it to a "real" DB. He was aware of the newer smaller boat and really wants to try that. He outfits pack trips in Idaho and was talking about getting one to leave at their back country camp. I'll ask him if he did next time we talk and get a report if so.
The other is fairly new to boating and didn't like it at all. My interpretation of his non-boating comments was that it didn't track well (which makes sense given the very rounded chines) and was heavy and hard to set up. He now wants a raft.
I'd be super interested in the small one for a 2 man fishing/hunting rig but the big one just seems too big. I bet we see significant changes again next year as they dial their design and production. The big thing design wise to me are the chines - (side to bottom connection) - on most hard boats the chine design dictates a lot of it's performance characteristics and these differences are all on the "much sharper" end of the spectrum than the very rounded chines of this boat. I.e. the freestone has like a 2-3" radius on the chine (I'm guessing from memory, but close) while a traditional rounded chine on a hard boat is like 3/4" - a "hard" chine is just barely rounded (1/8" ish or less) some even have chines that extend out. Kayakers should follow this issue as I believe kayak chine design follows similar logic to DB's. The current design point towards a boat that spins well but will constantly need to be maintained or it will spin (poor tracking, like play cat). It will also be less laterally stabile than sharper (sometimes call harder) chines - i.e. more susceptive to side to side balance issues.
The last issue, which is probably not an issue in most fishermen's minds, is that the thing is an entrapment hazard mine field. I think you still want to treat it like a hard boat - DO NOT Flip it - bad things might happen.
Yesterday's gone on down the river and you can't get it back. - Agustus McCrae