I would get frustrated if I had to set up an ally deck every time I was using my SIB and I know I wouldn't use it as much if I was on my own.
I understand some people's concerns about an airdeck when fishing, hooks knives etc, but I put EVA mats down on my airdeck to protect it.
The new T38 looks an impressive bit of kit, probably faster and can handle heavy chop better than my SIB, but it has a V shaped internal deck. Personally I wouldn't get one for the way I use my SIB. I want/need a flat deck, for the dog and for my other half. There is a "bilge" so the deck doesn't get swamped with water, and I find it easier to stand up in the boat.