As for ease of use, I'd prefer captain's seats. I've got a middle bench, and I wish I had captain seats. For one thing, I HATE having to pick which kid gets to go in the middle position in the vehicle. For another, I know that I've talked to lots of people that have Regent's intalled in them. If I had them, I would have most likely gone ahead and gotten 2 regents/huskies instead of a Husky and a Marathon. It'll still work out fine in the long run - the baby will probably get this Marathon and I'll either get another Regent for Mikayla to move into or I'll move Aaric into a booster. Its possible that 2 regents would have fit side by side on the bench, but it would have been a VERY tight squeeze so I went with the MA instead.
So from the perspective of a bench seat owner, I recommend going for the captain seats. I think it would also help with the "she's touching me!!!!" battles of long drives LOL.