I'm 158 cm (5'2") with inseam of 72 cm (28.35 in), which seems to be quite normal according to a formula . Riding Fuji Finest RC XS (44cm) with the effective top tube of 51cm and a 9cm stem.

I also prefer a WSD. This frame is only slightly compact and the bike comes with the compact handlebar for shorter reach and Shimano R-700 shifters for small hands. Shimano R-700 is important for me since my hands are quite small.

MS1, IMO, a 48cm is too big. Beside the reach, don't you need to consider the stand over height? Hmm.. I just checked Trek Madone WSD. Mine is about their S(50cm) based on the effective tt length and stand over height. (How do they come up with the frame size of 44, 47, 50 cm etc? Based on what? )