I got mine about a year ago, I pre-ordered direct from RC4WD when they announce it, with a 10% military discount.
Mine are all the same firmness - and were already installed inside the tires, no extras in the box.
Did yours come with the aluminum upgraded Panhard bar?
RC4WD emailed me some time later and asked if I still had it - when I confirmed that I did, they shipped me the Panhard upgrade free of charge.
I gather some people were having issues with the plastic Panhard breaking very easily.
I'm doing my usual slow-as-molasses build, where I order parts for a couple years and eventually start reassembling them...
I have not driven mine at all yet - I did the same thing with my Bomber kit, only took me 2 years to finish it!
The only stock parts used in the end on that one were the cage, the skid, the rear sway bar, the fuel cell, and the electronics box.
I'm not going that crazy on the C2X, but the electronics, driveshafts, and wheels and tires were the first thing I removed.
The stock wheels and tires aren't bad, just not really my style - I'm thrashing them on my Element Enduro Sendero right now... good grip in most situations!
The sidewalls are infamous for wrinkling really badly when stuck in a bind - I found that doing some quick reverse-to-forward accelerating would get them back to normal.
I did disassemble and reassemble them to see if there was something odd with the foams, didn't really notice anything.
If they keep doing that in the long run, I may sprinkle some talc between the foams and the rubber or something, to allow them to move more freely.
Enjoy your C2X!
"thumbsup"