From my own collection:
Overrated: Speedmaster. After all, a vintage handwinder, not really water resistant and very easy to scratch the crystal. Yes, I know that it's all for a reason (flights in space). But without the NASA heritage, the watch would have gone down in oblivion, like other Omegas from that era. The reason why I don't sell mine is the fact that it was my father's watch.
Underrated: Sinn EZM2 Hydro. The oil filled quartz watch. Absolutely accurate, tougher than old boots, wonderful effect of the oil under the crystal making it easy to read under water and under all angles.
Menno