Hi Mark,
While I am a rank amateur with regards to daylight digiscoping, I have a fair amount of experience with AstroPhotography, and have used my Celestron 80ED with great results. The various Synta made clones have a dedicated following in the astronomy field, as high performance per dollar scopes.
A benefit of the C80ED over the Ultima (at least it used to be) is that the EP's are removeable, allowing for prime focus imaging if you desired. The Ultimas could only image afocally (Through the EP). The downside is that it is fairly large and heavy, as far as spotting scopes go. (Though the C80ED is the smallest of the Synta clones)
The focuser on the Celestron 80ED is the standard Synta single speed Rack and Pinion, which is servicable, but not outstanding. Regreasing with good grease helps a ton. I have upgraded mine to a very nice dual speed Crayford focuser.
I personally much prefer an Apochromatic scope for imaging purposes. There are many discussions as to whether or not "ED" glass confers "Apo" status to a scope, but to my eyes, if not, it is pretty darn close. I can see no CA when viewing, and barely a hint of it with long exposure imaging.
I plan to get a better terrestrial camera in the near future, and take some shots of birds (I am just getting back into birding after 20 years or so), but here are a couple of astro images I took through my 80ED (reduced in size and quality).
Sooo..while I can't comment directly regarding the Ultima, I believe that decent images can be had with the Celestron 80ED. I believe that there are a few other posts here with 80ED images as well.
Regards,
Gary