Of late, I've moved to shaving first, then shower. For me, the pre-shower really just doesn't make much difference for the shave. I wet my face really well (usually with my brush), then do a couple of other tasks for maybe a minute or two. I face lather, and put the soap right on my face (shave stick), so I get a lot of brush time on my face. I really can't tell a difference from doing this, over shaving after the shower.
I like showering after, because it's the only way I can really get my face rinsed off well (without making a terrible mess at the sink).
James - 2011 R41 w/Ikon Handle, Feather, Arko (face lather), TGN Super Silvertip brush, Alum Block, Witch Hazel, Gillette Sun-Up AS
BOTOC - LOSER - SSB - ARKO - TOFLAC-U