I have seen a few 24-28s for sale. I am familiar with Donzi, Fountain and Scarab. How do the Ultras compare to each in performance and value?

ultras are a lake boat and not designed for any type of spped or wve jumping. their handling ability in such type of boating is less than desireable.
they are however pretty and quite frilly.

Thay are not really comparable boats at all. The Ultra is a West Coast semi custom boat built for lakes. I work on them almost every day and they are well built boats and thier rigging and gel work has only gotten better over the years. They are not an "offshore" boat at all though. If you do decide to buy one make sure it was rigged by Ultra and not West Coast Ultra, for a while Ultra was selling them hulls and letting them rig them then selling them under the Ultra brand name, they had alot of problems. Mostly really bad rigging and a general "we don't care, it's not our name behind it" attitude. Now Ultra stills sells them hulls but they no longer let them market them under the Ultra name, they are called Lighning now and they have actualy improved alot over the last few years.