Some good advice all round on this topic. Presuming you have read the sticky (Which SIB?) as it's a general round up on there aimed at prospective owners like yourself.
If I was you and really thinking of committing to a brand new outfit I'd really spend some time looking at fully inflated boats to compare and *definitely* having a go at assembling/disassembling each type - and remember all lovely in a dry showroom, different story when all dripping wet, sandy, tired etc...
Most SIB owners rarely get the right outfit the first time, hence why so many of us say go secondhand first, try it, see what works and doesn't and move on from there. This is why there is an endless stream of barely used outfits on eBay all year - carpeted showroom seduction is a powerful thing - bouncing along, uncomfortable, wet, tired can be the reality for many and the old saying the happiest two days of a boater's life: "...the day they buy the boat and the day they sell the boat..." can be just as true for SIBbers as the big boys....
And be sure to try manhandling a few engines - the weight is one thing the unwieldiness of anything bigger than a 2 stroke 15 is something else.
Pulling a rig on a concrete slipway on transom wheels (one man job) is a gazillion miles from trying the same on a beach/shingle/mud etc (3 man job).
Re' airfloor vs hardfloor - again, see the sticky but it's *essential* the air pressure in a HP floor is at the max or a tadge over with a proper gauge - 1/2 psi too little makes a huge difference.
On the 3.8m Honwaves there have been a few reports on here over the years that even correctly inflated they are inferior to the 3.4 and a bit prone to floppiness.
As mentioned above by beerbelly a rubber floor covering improves airfloors a lot, some pics of mine here:
Bombard Aerotec ready for the maiden voyage (b@stard son of a Y Class)