+1 for toptube length.

however, the higher the standover, the less seatpost you'll have to run, thereby lowering the saddle to bars ratio (unless you like your stem raised up a lot, most ppl don't), which makes for a more comfortable ride on the street. standover isn't as big of a deal on a track or road bike as it is on a mountain bike. . .

but if i was doing mad skids and tricks, i'd get a slightly smaller frame for bail-ability. but i'm not.

fyi, some people on the track race with smaller frames to get a super aero tuck. the polish national team trains at the san diego velo, so i see them all the time. they ride frames that are waaaay small, with at least 12+" of seatpost?! of course, this is totally ******** for the street. anyhow, that is why you might hear people say to downsize for a track bike.