I like MOS and the Pegasos is an impressive board, just as good as the XE it seems.
But I have my own idea of where MOS is going and I don't want to go there. This isn't to say it doesn't have a future, it does. But if I bought a Pegasos and waited 3 years down the line I have a very strong suspicion that the only software for it would be rather poor Linux ports. This is MY OPINION, so flames will be ignored or ridiculed.
I'd rather see what OS4 has to offer first.