If you fit your bike well, it will do well under many different conditions. At 5-1, I'm planning on using my 44cm Ruby for crits next year. I've gone so far as looking for more speed with a 45cm Colnago, but my Ruby fit better than anything.

It's a versatile little bike. Mine weighs in at 15.9 lbs and climbs like a goat. She's also aero enough that my 112 lbs can reach 50mph on a downhill (although admittedly 45-48mph is more common).