The usgi improved combat shelter is a good enough unit. I purchased that and the usmc tcop, along with a lightfighter last year. The lightfighter is a pos(fly seam just ripped in half) thankfully ebay seller let me return it.
Ok one thing I learned is that the coatings(on all tents) will degrade, even if it's new/unused. Thankfully the improved shelter was and is great shape. My usmc tcop is degraded badly. The inner coating is sticky and flaking peeling off.... outside and material wise it's mint. Same with a usmc tarp in marpat.... too bad it's really sweet looking. I have cleaned and applied some polyurethane(like the wood finish crap) to the inside of the tcop fly..... so we will see how that works out.
I have been using my improved shelter off of the motorcycle, and for multi day trips on the jon boat up rivers ect. It's a bit of a strange little tent, but I like it. I would also like to aquire a non degraded tcop, or maybe I should try one of the two man. As far as I'm aware there isn't anything on the market for a true 4 season tent that isn't in some color that would be found teletubbie epesode.