The A50D is old tech and that's what put me off buying one - like I said there's nothing wrong with them, but if you can get upgraded units for the same/similar price why not.
One big thing you need to consider though is water resistance and how it will hold up to the conditions on a ski. Most fish finder head units are designed to be installed in a relatively dry boat dash. On a ski the FF is very exposed and can get very wet, and sometimes with the speeds you do salt water can be effectively blasted at the head unit. On the FXHO, I could be wrong, but I don't believe the head unit can be flush mounted on/around the glove box (like Coxie's??), so it will be very exposed. I've got a cover on mine which keeps most of the water off and prevents water being blasted into it.
So could pay to check with the dealer whether whatever model you go for is suitable for a ski, or even if it could void the warranty being used in those conditions??
“My biggest worry is that my wife (when I’m dead) will sell my fishing gear for what I said I paid for it.”