Advice on mount purchase

So I think I'm ready to make an investment in a mount and I've started to check out options.  My current setup:
Scopes: Celestron 11HD, TS130
CGEM-DX mount (hyper-tuned) mounted on permanent pier with WiFi/LAN connectivity (live internet also)
Various cameras, hyperstar, guiding setup, etc.

My budget to invest is around $6,000, and that includes selling my CGEM-DX at some point soon.  My goals are to get something with improved pointing accuracy and tracking, and something I can operate remotely as much as possible.  I'm also pushing the weight limit on the CGEM, so I need something that can support minimum 60+ lbs.  So far, based on what I've researched on the vendor sites and in the forums, I'm considering the following as options:

Celestron CGX-L ($3000 new)
Pros: Cheapest option, supports wifi module, dual dovetail saddle,
Cons: No LAN connection options, no USB 3, no powered USB2?
Performance?

AP Mach1GTO ($5500 used)
Pros: excellent tracking/pointing, PC4 control box includes LAN/WiFi
Cons: used, okay for permanent mount?

iOptron CEM120EC ($5500 new)
Pros: heavy payload support, good/avg tracking?, LAN/WiFi support
Cons: US support?

Paramount MX ($6000 used)
Pros: excellent tracking/pointing, 
Cons: used, most expensive

Here are my questions for you:

1. Are there options that are important I should consider?
2. Mounts that I should consider that aren't listed?
3. I like the idea of buying new, but I also like the idea of getting more for my money with used equipment - what has been your experience with the lifespan/reliability of AP and Paramount used?
4. The CGX-L is pretty new, what has been your experience with it?
5. This will be permanently mounted on a pier in a roll-away observatory in Ohio - any cautionary advice on operating in humid/cold conditions?

Thanks in advance!

JW

90% of my astro gear was purchased used including all my mounts.....no regrets on that front.

Out of the list you posted the Mach1 would be my choice without any reservations. Nothing wrong with the paramount, I am just not a fan of their business model. The other two simply are not in the quality range of the Mach1 and their support is 1st class.