Well, is the F-type hard to sail comparing to your 145 Carve...
Can't really answer that as I haven't tried the other board, but I'd say if you are talking about serious exploiting the FT I'd say yes, it is considered a more technical board.
It allows for amazing upwind angles.
I tried a 130 or so freeride board ones and it was plug&play comparing to my FT. It has a large, powerful fin, straps are very out and back and it can get pretty handful at chop, unless you have a 10.0 sail which will get you on plane on flat water - with 7.5 and my skills/weight it gets more demanding.
Anyhow I love the board, haven't mastered it yet, but sometimes when I get dialed in it just blasts upwind with great speed and wants to stay on plane all the time. The other freeride board I mentioned felt pretty boring comparing to it.
Just my 2c.