I don't know what you agreed to pay for the V10 but after seeing the photos inside and the specs on your jeep, you just downgraded in some respects. You are going to a vehicles with less mpg, less cargo space, no full size spare, no touch screen nav, but costing considerably more $.
With the v10 you're getting a lot of fun and air suspension which based on your taste in wheels on the Jeep, you may never fully utilize anyway other than just for kicks - meaning you probably don't "need" it.
The Jeep is more able to be modified for rugged use, has a longer flat roof for better rack systems, and the spare is already tucked away not using up space.
I don't understand except that I have done similar dumb moves - probably why I'm reacting to your choice this way, so don't take it personally. What's "wrong" with the Jeep? You could do a medium spring lift, proper wheels/tires, and have a great trail tourer.
Maybe I should buy it for a project vehicle!
Points well taken, however my rationale on this one is bullet proof.
a. I am not happy with Jeep's design in many parts. I do not like old school Sprinter transmission that shifts like hydromatic Chevy, I do not like awful bouncy shocks and struts, because these 18" wheels are super heavy. I am also not happy with rock crawler gear ratio, that makes my Jeep spin at 3000 rpm, while going 80mph. Overall these 40% of Mercedes is definitely not enough to make this vehicle fun for me, however someone will love it to death.
b. I am trying to capitalize on VW's marketing mistake of making $75K vehicle under VW logo. V10 was more of a statement, than model and when they fixed all major bugs by the end of 05, it became a truly overachiever in its class. There is not much to comare it to, it is like Porsche 917 with 4WD.
I know it will suck navigation wise, like most Germans do, it will not give me more than 20mpg and it will cost more to maintain. However, I will have a luxury ride, more features than Mercedes S class and so many foot pounds of torque that butterflies will never leave my tummy

c. Last but not least, cargo space of GC is lesser than that of T-reg. As the matter of fact, Toyota Highlander has more cargo space than the GC.
BTW, I got my GC when diesel was nearly $5/gal and dealer in NC could not give it away. So if I sell it now for $28-29K, will only be loosing around $5K in depreciation, which is less than if I bought Honda Pilot, or some other trendy crap with tin foil metal on it.