RE: Which board should i choose carve 144 vs go 170
I doubt a C144 are comfortable in 20-30 knots of winds? Must be a very flat water spot with smaller sail than the board is made for. The same goes for GO 170. I haven't tried the C144, but I belive the biggest difference between those boards, are that C144 will handle chops better, and thus a bit more wind and rough conditions. I do not belive in buying a board that last for more than "3-4 months" when one are new into windsurfing. I suggest going for a solid board that makes learning everything easy as possible, then buy another smaller board that lasts for years. C144 are also more fragile and prone to catapults if I am right.
The GO 170 and a 220 litre board are quite different.