I have a CEM120EC2 as well - for about 8 months now. I see that we are shooting with the same OTA at the same focal length. Do you mind sharing your settings in the options tab? While I'm at a lowly 500 feet above sea level, my guiding very consistently issues pulses to the mount and while my guiding can be <.5" it is often greater than that and approaches 1". While my stars are still round, there are frames where the bloat is visible when blinking a nights images. As a result I'm constantly fiddling with the options settings trying to improve performance. One thing I notice is that you have your guide camera set up for 1x1 binning. I've gone back and forth and am currently at 2x2 and getting ok results.