I def wouldn't sell your HA-1. Didn't that take a while to obtain?
Then Senns and the K340 really are no problem to re-optain should you regret the decision. Todd does bring up a good point about the KGSS.
In the summer I keep my room at home at 60*. The apartment is usually 64ish about this time of year, and in the winter its usually mid to upper 50's. I like it COLD. I'd much rather put on clothing to keep warm, then to not be able to do a damn thing except sweat since I'm hot.
We mainly keep it so cold in teh winter to keep the heating bill down (we have electric heat), but I sure don't complain. COLD is for me.
IMO his new Elements of Life is weak compared to older tiesto. I would check out Magik 6: Live from Amsterdam, Nyana, Parade of the Athletes, and his entire In Search Of Sunrise series (including number 6, which is amazing, IMO).