Matt, I have flown Insel twice out of Charlotte. As far as luggage and on time history, for me they have been neither better nor worse than any other airline. They all cancel or arrive late, they all misplace my luggage, they all always have a reason for the problems. Insel is older planes and are a little more worn but the staff has always been very helpful and pleasant. Getting through to someone is a problem and they do not keep accurate flight times posted. When we book I will only do it through a travel site so there is an intermediary to run interference if needed. I use Travelocity and so far that has worked well. If the flight times are best and/or prices better, consider them. If price or flight times are not significantly better, I would probably go with one of the larger airlines.
Luggage is limited if you just do the island hopper but if your flight originates from the USA, the luggage allowance is as good or better then other airlines, especially if you tell them it is dive gear.
Hope this helps...
