I as well have a big agnes and use it all the time. Works well. I had a thermarest and didn't like it but have had the q core for 4 years with zero problems. So I guess when it boils down to it its just a preference thing.
It's not a bad tent but I was trying to cut my weight down. Zpacks makes there tents out of Cuban fiber which is lighter and more waterproof then sil nylon. I've set my tent in the shores of Lake shoshone up in Yellowstone and it was Sandy and I didn't have a problem.
It really depends how much money you wanna drop. I went with a marmot limelight that was about 6 lbs when I started. Then to a big agnes Copper spur ul3 that around 3lbs 9 oz. Then I dropped a bunch last year on a zpacks duplex thats 20 oz and love it, all though you need treking poles to do a...
Did the wave last November. Had put in 16 Times before we drew out. All I can say is good luck, it's tough. You'll have better luck to put in on the weekends and in the winter months.
Not sure on the millage but one day on the highline last year we camped below kings and in one day went up Anderson pass, went to the top of kings, went over tungsten and over porcupine and down 5 or 6 miles to camp. So three passes and kings in one day. It was awesome.