Bike Fit: Or, What's the difference between a 54 and 54S Fierte?

[DAG]

Shorter TT, or shorter stem? I know, MMV.

BUT: If I typically like a 530 TT, what are opinions about going for a 535 frame/ 90 stem versus 525 TT/ 100 stem?

[BCS]

I have ridden both of these combos. I still have a 54S Ti Fierte. No way that I can tell any difference, YMMV. A 54 may be easier to sell in the future.