TotallycasualDon't feel bad. They're two entirely different headphones. If you plan to use them while commuting or traveling, the the Bose QC35 is the better choice.
TotallycasualI wouldn't mind having both, and I'm not a gear slut or collector, but those two headphones serve entirely different purposes IMO.
Anyone really into their music could stand to use a nice closed pair for on the go use (with or w/o BT, NC, etc.), and/or a pair of IEM for more portability (depending on comfort etc.), plus a nice open headphone like the HD6XX for home use (if you acutally use headphones at home anyway).
Once you go beyond that or own more than one pair of any of those three kinds then you fell down the rabbit hole... Stay away from the edges, don't look into the darkness!