Id not recommend the Losmandy with Gemini II system unless you are pretty good at figuring out how new software works.
I've know 3 people now who have had the Gemini II system, 2 of them never got them to work properly but one figured it out and enjoyed it. He is a software developer, which might account for why he figured it out.
I've had a dumb G11 for the last 20 years, the non GoTo mount, and its an excellent mount and very well made.
Two years ago due to light polution, I bought 2 GoTo mounts, the AVX and CGEMII. Both are extremely easy to use and work flawlessly. I cant imagine anyone making a simpler fully functional GoTo system then Celestron.
If you are willing to take a stab at learning how the Gemini II systems work, by all means go for it. I don't think I'd have any problems with the Gemini II systems but don't need it.
Technically Savvy people wont have an issue with the Gemini II System, just be aware that it isn't a simple walk in the park like your CGX is.
I would recommend getting the CGX repaired not just to save money, but because its an excellent mount and you are very familiar with it already.
x2 what Ross said.
If you decide to replace the mount, I suggest you look at the Losmandy GM811G which is higher quality than what you currently have. The GM811G has an imaging weight carrying capacity rated at 50 lbs. It is pricey, but you will never regret getting it. I love mine. That being said, learning the intricacies of the Gemini 2 controller will take some time. Good luck on your decision.
EDIT to include add'l info on the Losmandy GM811G:
The mount head in standard configuration weighs 27 lbs. However, if you purchase the RA axis extension ($295) you get two benefits: The "RA Extension Kit is used to allow a Meridian Flip Through. This is done by adding an 1.5" to the RA body and also raising the Saddle Plate by 0.6" . With this kit the motors will not interfere when doing a Meridian Flip Through. An added feature with this kit is the ability to easily remove the DEC axis. This is useful when transporting the G11 to break down the G11 into lighter more manageable pieces." IIRC, the DEC axis weights 11 lbs and the remaining mount head weighs 18lbs. The entire mount with the heavy-duty tripod (35 lbs) weighs 67 lbs, but this is not a concern to me because it all rides on a Scope Buggy. Due to my bad back, I no longer lift anything over 25 lbs. You could make your GM811G rig even lighter by using the light-weight tripod at 15 lbs. All in, my rig cost four large.
Note: The quoted text above is from the Losmandy website.