I was also looking at the 949. Did not know if higher price was worth it over the frabill.
I haven't seen the frabill in person so I can't say for sure. The other one I really considered was the Shappel 5500, but when the 949 went on sale locally (under $200) I ran out and grabbed one. It's huge, very roomy for two people, I've had 3 inside fishing and it was fine, 4 would be tight in my opinion . I have the uninsulated version.
Maybe just my opinion, but on a pop-up I consider a 3 man is good for 2 people, a 4 man is good for 3, etc. Just like camping tents. I mean, you can get that many people in, but if you're at any depth of water you're so close together you're going to snag each other and likely be keeping some of your gear outside just to have room.
Like Hardwater mentioned, the only thing I don't love about it is that it is long when it's folded up. The bag has straps so you can wear it like a backpack but I wouldn't plan on doing that for any length of a walk.