Gaited trees, in addition to having a higher gullet (as gaited horses tend to be high withered), have more rock and are wider in the front of the gullet than in the back (done this way to allow for more shoulder movement). Arabian trees have narrower gullet (like semi QH bars) but flatter pitch angle (like on full QH bars).
Every horse is built differently. Certainly it's not a bad thing that a gaited horse tree fits your horse, just as it's not a bad thing that a gaited horse tree won't fit my gaited horse.

Gaited trees don't fit all gaited horses; Arabian trees don't fit all Arabians.
Use the tree that best fits your horse regardless of what it's called. It's a good thing that you found a tree that fits!