I recently purchased what may well be the last new CEM60 in the US. I was happy to get it as I needed something with a good weight/load ratio and wanted higher capacity (and non-EC) compared to my CEM40EC. The CEM70 is 10% heavier and too new. Having used a CEM40EC for a few months, I found the CEM60 easy to learn and use.
My first target was the Crescent Nebula, which I imaged over three nights from my Bortle 8 Chicago suburbs location. Included are 39 x 180s and 58 x 360s for a total of 7.75 hours. Other details: iOptron Tri-Pier on a concrete driveway, iPolar, Meade 8" LX90 ACF, ASI 071 MC Pro at -10C, ASI 290 MM Mini on ZWO OAG, Optolong LEnhance. Software: APT, PHD2, PixInsight.
Compared to the CEM40EC carrying the same equipment, I get noticeably rounder stars, which was one of my goals with the CEM60. I'm getting about 30% higher rms in RA than in DEC (0.32" and 0.25" are typically) and unsure what to do about that. Seeing was not great, but not the worst I've seen. I'm hoping eventually move up to an 11" Edge HD on the same mount. I use the PPEC algorithm in PHD2 for RA and bin the ASI290MM, which seems to help, but the OAG often gives distorted star images even when focused. Is this normal with an ACF scope?
Alas, last week the RA stopped moving on my CEM60. After discussion with iOptron support and help from OPT (the retailer), I got a new RA board from iOptron and it is up and running same as before.