First off, I''d like Richard to add where he found the Aqua Pro dink to his cost comment; sounds like it''s worth investigating.
Nuka, we just finished using a 10''6" Achilles LSI dink for 2+ years while cruising the Caribbean. The basic concept - a compromise of collapsability, weight and speed vs. a non-rigid floor - is exactly that: a compromise. We chose it because it would be eaiser to bring aboard/stow/launch than a RIB (it was, by far) and could be deflated when offshore (in retrospect, not so important as I thought).
Just about everything on the dink broke (rowlock, towing eyes, 2 floors at the valve attachment point...I could go on) but, in fairness to Achilles, they did replace things even beyond the warranty. And keep in mind that Achilles is the only inflatable dink with a Hypalon floor (at least as of our purchase in early 2000); even Avon was making PVC floors, which didn''t seem a good idea given all the U/V the dink was going to see.
We powered it with a 8 hp Yamaha 2-cycle and it had more than enough speed...but it was wetter than the larger-tubed ABs and similar.
Picking the perfect dink is so tough it makes picking the perfect sailboat seem actually possible.