I have a 3-season Burrow and Crowsnest/Phoenix. They are warm! I sometimes wish I had gotten a summer Burrow instead. Although I can unsnap the foot box, stick a leg out, etc., I do get a little hot on occasion when it's still too cool to just take it off. The 3-season Burrow is true to its temp rating and kept me warm down to 14* at the NJ Winter Hang.
I'm not sure how well this is actually working, but I have tried to shake the down out to the side to de-loft the center when I get too warm. I think it's helping a tad.