Hi Lee
You mentioned that you will using a GM-8 for photography, a couple of things to take into consideration here. Do you know the all up weight of the equipment you intend to use on the mount, ie: OTA, camera, quidescope, rings etc. The GM-8 has a load capacity of about 15Kgs/30lbs, the normal consideration is that the weight of all your gear should not exceed 2/3rds the carrying capacity of the mount. The weak point of the GM-8 is the tripod, whilst sufficient for normal viewing, IMO it lacks when used for photographic work.
All new GM-8s and G-11s now have the high precission worm so PE is not a major problem as it used to be, the latest Gemini system is Level 4.02 and the PEC apparently works well together with other fixes.
I have both a GM-8 which I use as a grab and go mount, no Gemini or DSCs and a G-11 with Gemini, this is permanently mounted and used for photography, being guided with an ST-4. I have had no problems at all with either mount or the Gemini system as such although there is a steep learning curve. You will probably have to learn how to make adjustments of the mount but they are simple to work on.
My advice would be to save a little longer and get the G-11 if you can afford it, the payload is double, 30Kg/60lb and in the field you can kick the tripod and it will not move, absolutely stable. The other thing is to think about the future, do you intend to upgrade equipment etc.
Cheers
JohnG
