I bought the ma790 to use when it's horrible..
I bought the ma790 to use when it's turbulent, choppy and overpowered where I live and for in waves when on trips, I basically haven't taken it off since I got it though!
I've got the ha680and 880 and I use those with the dart 140 mainly and sometimes the 180, and I use the 790 with the surf 130.
It just feels more fun to
Ride in waves and when it's horrible conditions, it handles speed better and turns amazingly, Pitch stability is great.
Glide is a little less than the ha but still good and it pumps different (slower deeper pumps) but I'm really enjoying using it overall.