Originally Posted by
cmc4free
You mentioned bulk as the main reason for wanting a 3/4 UQ. If budget allows, you could get a Premium Phoenix 30. The 10D fabric compresses much smaller than the fabric in the Econ line. I'd wager a Premium Phoenix 30 with 850FP packs down smaller than an Econ Phoenix 40 with 800FP. Yes there's a slight difference in the down, but the fabric will make a bigger difference.
If you're wavering between 30/40 and planning to get the premium version regardless, then you might just want to get the 30 to be more conservative. That said, of all my UQ's, the Premium Phoenix 40 with 950FP +1oz is my favorite.