Well.... the frame is a 48cm and I am using a 12cm stem.
I am pretty small at 5ft5" / 5ft6" but I have 'stumpy' legs and a long torso.
The next size down in the Colnago is a 45cm - but this has a 13mm shorter top tupe but a steeper STA (75deg30 vs 74deg30) .... I was concerned about getting the proper saddle set back and top tube length.
I am already running a 12cm stem so I played safe and went for the 48cm.
I previously rode a 47cm Colnago Dream and the 48cm was the closest in terms of geometry etc.
I have the opposite probelm, I have short leggs too but my frame is too small for me.
".....but our amps go to eleven"