I checked out that t-rest chair for my Husband...he's all about the lightest weight possible.
But the catch is, we do not use Thermarest mats, and the mats we use will not fit in that chair.
The other part I'm not fond of, is the sitting on or low to the ground.
With the Monarch chair, I was able to cook over our Jet boil pot, mess with the camp fire, dig in my pack at my side, kick my legs out in front crossed at my ankle, or cross my leg over my other like sitting on a couch. It is easy to get in an out of, even after long hikes, and my body is tired, drink in hand. The Material is wind blocking, so no real draft underneath when sitting either.
Ok..enough said about my luxury chair. But the T-chair does have the Lighter advantage. by 12 oz.
T-rest 6oz + pad wgt