Bushido
·Here's a reason - It's the first production black/white reverse panda dial speedy in Omega history.
Another is that means the watch is far more visually striking and unique than either the silver snoopy or the 60th anniversary.
Here's another - it also has a host of other features that are tailor made to drive collectors wild: appliqué logo, vintage crown, vintage script, radial subdials, brushed case, vintage buckle. The others also have nice details but none have quite so many as the ST.
Personally I couldn't care less how it performs on the market, or how the other watches do, nor do I much care to face off three nice watches against each other. But I think there are plenty of reasons, and plenty of reasons already expressed by many people on this thread and in the wider forum to justify why the ST is expected by many to be the hottest new Speedy in years, if not ever.
I was going to reply and list out my personal reasons for finding the ST as awesome as I do. However, @N1CK aptly listed them all out very well! Ergo, I'll simply state "+1" to everything he said.