RE: I sonic 145 VS F-Type 138
I can appreciate what's you're saying here. Frankly, I personally don't like stuff that's too fussy and narrow in application, as you can often feel you're on the wrong side of the equation. However, a good slalom board doesn't have to be high strung and tough to work with. Yet, finding the right rockerline isn't always that easy. I've been very lucky with slalom boards (never a miss), but for a number of years I had a tough time getting a surfy freeride board to my liking that was fun to blast about on but still could be maneuverable in lightwind surf conditions. After 3 failures in a row, surprisingly, it was my slalom board shaper that came up with the right solution with a versatile freeride design that offered a very friendly balance that was fast, easy to ride and still quite maneuverable in waves.
Getting back to the heart of this thread, there's an important issue to keep in mind. I don't want to dwell on a bunch of negativity, but in my opinion, I think that the yearly change mode so common today across many of the production brands can have its real disadvantages. The next years' design tweaks don't always offer a better product. With things constantly in flux, it makes things very tough for a sailor to find that perfect product and then feel good over the long haul. When I buy a new board, I intend to keep it for 5-7 years at minimum, so I tend to be immune to the yearly hype and the whole fashion of having the latest and greatest. Sounds to me like your brother would do well following a similar strategy.
Of course, that doesn't solve his problem of finding the perfect design. I might be out of school here, but has your brother looked into the higher volume Carbon Art designs. Phil McGain is a real demanding guy, and sailing in Maui requires really balanced shapes to handle the challenging conditions. CA might be an interesting avenue to consider. The fact that you have already stepped into that arena with your speed boards might offer some added dimension.