Thanks for the input. Much appreciated.
What mount do you use it with?
Do you have the rack and pinion focuser?
Any reducers or correctors?
What camera type, maybe aps-c size, and how much vignetting?
I use an iOptron CEM70. I typically use a ZWO ASI2600MC and get 0.5 arcsec rms guiding and sometimes as low as 0.3 arcsec when the seeing is good. This setup is resistant to wind up to about 10 mph. So, it's pretty heavy, but well worth it for the stability. Long OTA's need this.
Mine came with the so-called "TS 2" UNC V-Power Newton Crayford Focuser - short". It works well, but I have added a ZWO EAF. The performance with autofocus does make an improvement over long sessions with large temperature changes.
I currently use the TS Optics 2” Maxfield 3-element coma corrector 0.95x. This is really excellent and highly recommended.
With this camera, I do see typical vignetting which I always correct with flats. Getting good flats with a Newtonian can be a challenge, but that's another topic.