I dreaded putting the 110ED on my AVX - I see the guiding graphs everyone is getting and I wasn't getting them as tight. I figured the added weight would overload my mount and the stars would be horrible. But my guiding is much tighter ... I went from a dec correction every 5 seconds to averaging one every 80 seconds!
It's a different refractor - but still a refractor. With the AT65EDQ I found the stock counterweight too heavy, so I got a lighter one from Orion and use that. The scope weighs less than 5lbs, with everything (scope, camera, finder, guider, counterweight, etc), I'm putting just under 15lbs of weight on the mount. Swapping to the 110ED, I use the heavier counterweight, and the total weight goes up to 36 lbs.
I'm setting things up the same way as before - using 2+2 stars for calibrating, ASPA for PA (I didn't bother with alignmaster last night just to make it harder). Yet my guiding graphs are flat! I changed focal length and camera settings in PhD, so it's not that. The only other change is I'm not using the OAG (I'd have to adjust the prism and I'm not going to do that unless I leave the scope on for a lot longer)... I'm using the SSAG with a fingerscope. If anything, I thought that would add to things being worse.
I don't know ... I'm not complaining about getting good guiding, I'm just surprised, and not understanding what's going on.