Vixen SD 81S, William Optics GT81 or...

[osbourne one-nil]

After many years of drooling, I got my SDX2 mount earlier this year. I adore it.  I bought it to make visual observing a joy and it's lived up to expectations. What's surprised me is how, by putting a camera at the eyepiece end of a telescope, it would yield very pleasing results.; I'm hooked. 

At the moment I'm shooting through a SW 130PDS, which is actually excellent (particularly for the money) but its 650mm focal length is a bit of a bug-bear. It's not got enough reach to get those tiny objects or enough field of view to capture nice wide nebula, so I'm in the market for a wide-field refractor. 

My heart says the Vixen SD 81S. I've always had a soft spot for Vixen stuff and it would complement my SXD2 mount nicely, although that is obviously totally unimportant. I believe these are excellent and Ed Ting agrees (assuming an SD 81S is just a refinement of an ED 81S). I don't think it comes with a dual-speed focuser (despite what FLO's page on it says) but I'm not sure that particularly matters. 

The WO GT81 is a bit more expensive but does seem to be better value by giving the dual-speed focuser, a camera rotator and more options for mounting "stuff" associated with astrophotography. 

I'd be shooting with an ASI533MC Pro and whichever scope I got I would get a flattener and probably a reducer too for the Vixen as I'd want to be around 500mm focal length. I would want whatever I got to be a capable visual instrument too so I feel this rules out the 60mm quad or quintuplet-type scopes. I know the 

Is either the Vixen or William Optics scopes objectively better than the other or is there nothing in it really and it comes down to subjective judgments? 

Thanks!