Full disclosure - due to the interminable cloud cover over the winter and spring I have not had a chance to use this mount for more than a couple of very short test sessions.

I decided to move from my Skywatcher HEQ5 (Rowan) because I wasn't happy with the guiding accuracy I was getting. Originally I was thinking along the lines of the Skywatcher EQ6-R Pro which would give me significantly greater load capacity; however, I was fortunate enough to find the iOptron CEM40 in a deal from FLO. I was concerned that the iOptron mount might not give me enough additional capacity but had some really helpful guidance from FLO (thanks Chris) and realised that the CEM40 would be an ideal mount for my 11kg imaging rig (I'm also not expecting to increase the weight of my kit so no need to future-proof).

On the couple of occasions I tested the mount it performed extremely well. The iPolar function seems to work well after calibration (PA error of 0 according to PHD2); and I was getting good guiding for the few minutes after set up and before the cloud rolled in.

I'm looking forward to being able to have a proper AP session!

As usual FLO service & shipment are peerless. The mount is probably at the max size I would consider portable or “throw and go”. If you’re small it might be a little heavy. Anyway, works great with both 4” & 5” APO refractors, very stable and ultra precise goto once it’s polar aligned. Even handles my StellaLyra 10” Newt. Not used for imaging just yet, but will be giving it a go for this on the next decent long cold clear night.

The mechanics and build are excellent - it is a beautiful piece of machinery. Updating the firmware is a real pain in the a*se, even when you know it’s a possible issue in advance, and updating the hand controller firmware requires you to buy a RJ9 to RS232 lead plus a RS232 to USB converter if you bought your PC anytime after the 1900s. Neither are included and there is no *modern* alternative. They’re not expensive - it’s just annoying that after spending the best part of £2k on a mount, there is no way to update the firmware with the leads provided. The included instructions were for the wrong mount too, but they’re all online of course. IOptron email support are distinctly failing to help on this either - though of course FLO have helped as much as they could.
Once you surmount these teething issues, it’s a great mount and I would recommend it - especially if you need portability with 18kg visual or ~10kg imaging payload capacity.

We have had a recent disappointing experience with a CEM40 we ordered. In the end we sent the mount back and asked for a refund which we received no problem from FLO. We just want to make anyone contemplating buying this mount aware of a few things. It is likely that the mounts port configurations might change so please consult the iOptron website to be fully aware of any changes, also ask the guys at FLO to be sure that any current changes to the mount’s connectivity suits your requirements. We didn’t test out the mount so we assume its functionality with the handset is OK but we did have problems with a loose USB connection which is now the only one to the mount that handles all of the usb inputs and is the connection to the iPolar. Anyone also buying the case at the same time should note that iOptron will transport the mount in the case and so the it will not necessarily arrive in pristine order. We have given the mount one star to get people to look at this review it isn’t a reflection on how good it performs as we didn’t get to test that.

Received this mount last week, FLO were excellent service. I been out a few times under limited clear skies. The Ipolar works a treat, my first attempt getting 3.5 arc minutes within the NCP.
The tracking seems very good as is the goto's . Also only had a limited time guiding using ST4, but PHD2 was giving excellent results.
The 2 inch tripod is very nice and extremely stable.
all in all im a very happy man