When you open the quality aluminium case for the first time I defy you to not be impressed by the finish on the 66ED: it's truly impressive.
The gloss black is immaculate, if a bit of a fingerprint magnet! I do recommend you keep silicon cloth or similar to keep it looking good. When you pick the scope up you'll realise this is a serious piece of engineering. Based on a much loved design that was marketed by William Optics among others, this version has a much improved rack and pinion focussing tube. The machined aluminium body is much more solid than most of the scopes out there. There's a small trade off in weight of course, but it's worth it for a scope of this quality. and it's still light enough to use with one of the portable goto mounts like the iOptron Skyhunter that I use with my "grab'n'go" kit. Even the built-in dew shield is a class above what I'm used to. There's non of the slow slide back to closed when shooting overhead, even with a dew heater in place. The rack and pinion focuser is a dream you don't expect at this price. It's precise and stable, though the lock isn't the easiest to get to. I've coupled this with an iOptron iEAF automatic focuser which works great and negates the need for the lock. Do be prepared to do a little bit of modification to the bracket to get it to fit though.
The glass is great. I get nice round stars with little very little bloat or CA. Colours are beautiful, whether it's stars or nebulosity. This may not be FPL-53 but I very much doubt you can tell in practice. I'm using the StellarMira 1x flattener and the 0.8x reducer/flattener with my Altair 183C Pro TEC camera and I have have a beautifully flat field to all four corners with both. It is like having two scopes for the price of one! A word of warning though, don't be tempted by the 0.6x reducer as it won't quite reach focus unfortunately.
So far it's all positive, but I do have a few gripes, and they mostly stem from one thing: the mounting foot.
You will need a dovetail bar if you ever want to achieve balance. Once you add a dovetail, the built in rotator becomes redundant. It also makes it a struggle to get the scope back in the case. My solution is a Bressar dovetail clamp mounted on the dovetail bar rather than screwing directly to the foot. It just makes things a little easier to manage. I'm also a little disappointed that there's no guide shoe included, though this is a minor gripe and there is facility to mount two if required, a definite bonus and rare in smaller scopes.
All in all, this is an excellent scope that's easy to recommend.

Wow, what a wonderful little scope. I own a WO ZS73 and this is almost on a par with it!
I also went through TWO skywatcher 72ed and was plagued with tilt and spacing problems, not here..
Firstly it's really well made, really Chunky.
The glass is better than you would think, little ca, less than the 72ed.
Only issue is a stiff focus lock knob but with use it's starting to free up.
I put some images into ASTAP tools and was amazed at how good tilt and spacing were dealt with, superb.
I tested with a canon 250d and asi183, asi 585.
Image quality is wonderful.
I also purchased a set of the skywatcher 72ed rings from flo and they fit perfectly.
This scope is so good for the money I couldn't recommend it enough, it's def a keeper.
If you are in the market for a smaller widefield scope this is the one to get, avoid the skywatcher 72ed.
Using both stellamira 1 and 0.8 flatteners I find good spacing at 70mm, so ordered a 15mm extension for my asi cams