CO's domestic first is a good product, with 2 by 2 leather seating with adequate pitch.....on the short MSY
run, you will have a drink service and thats about it - not enough time to do much else.
First Class on CO
is very nice indeed - since CO
considers the IAH
longhaul segment equivelant to an international service, you will have an excellent meal service, very comfortable BusinessFirst type seating, etc. - all the extras including PTVs and good inflight entertainment (movies, the CSI channel and HBO offerings are my favorites). The 764s are a comfortable aircraft, especially upfront, but do note that the configuration of the 764 used on the Hawaiian runs is a bit different that the 764s used for other long-haul services (see seatguru.com); basically, the forward cabin is smaller (20 instead of 35 seats) which, in your case, is a good thing, as the service will be more personal.
My opinion is that for US mainland-Hawaii services, CO
is better than the other carriers since they operate the flights to international standards (as far as seating and inflight service) while other carriers simply consider the flight a regular domestic segment. Enjoy!