I had a bike shop fit me on a 13 inch Trek 7.3 originally. I bought one a couple of years back and had to get a new bike due to the fit being all wrong. I experienced a lot of back/leg/neck pain - as well as aluminum buzz that made my hands go numb. Ultimately it was too small for me. I'm 5'3'' My LBS told me a 13 inch should fit a 4'11'' - ish woman. Hoo-boy.
I now have a 520 and an Aurora both fit differently but fit well and I adore them both. The Aurora was a graduation/xmas present. The 520 was my re-placement bike.
"Things look different from the seat of a bike carrying a sleeping bag with a cold beer tucked inside." ~Jim Malusa
2009 Trek 520-Brooks B-17 Special in Antique Brown
2010 Surly Long Haul Trucker-Brooks B-17 Standard in Black
1983 Fuji Espree Single Speed-Brooks B17 British Racing Green