For me there's something special about Sven in the main room. The way he comes out fists flying, so much intensity in the first few hours...and the hour (ish) around mid-set when he'll go more deep and hypnotic, and then the weird-to-extremely-bizarre stuff once the sun is up in the other room. There were a few years in the late 2000s (07/08/09 sticks out) where those main room sets were just the most incredible stretches of music I think I've ever heard.
I love him on the Terrace too, and I like the sound he settles into there, but what's missing (admittedly for good reason given brighter environment) is that extra gear of rip-your-heart-out dark techno that I've heard him dust off in the main room so many times.
I also like his nighttime sets in the main room because it leaves more contrast for the music selections at the carry-on
I'll take Sven in either room over anyone anywhere else though!