I’ve had my 5500 (the size smaller) for going on 8 seasons and other than the bag sunfading because I left it on my porch all summer once, the hub itself is still in like new condition. Literally nothing is wrong with it. Great hub in my experience.
You and your brother will have plenty of room in a 6500. My 5500 is a pretty decent 2 man. Awesome 1 man. I’m 6’ tall and 240 pounds. Windows are at a good height to see tipups and have been durable. Zippers are nice and tough.
For what it’s worth, I bought mine before Shappell was sold to Eagle Claw so I can’t attest to current quality out on the ice but from what I’ve sat in in the store, it seems to be the same quality. I don’t think you’d be disappointed in the 6500.
I say get it now so you can use it now.