Different preference here: I used to like more H's solo projects, like his acoustic sessions in Gibraltar or his collaboration with Richard Barbieri. Rothery's solo... so far... left me cold. And maybe I should give Transatlantic another chance, but to me they the represent the cliché of what prog should not be.Yes, I believe Rothery is considering a 5.1 mix whenever he gets to finish his solo project. Sounds like he has delayed finishing it to concentrate on Marillion's next album.
I am sure you know that Pete Trewavas' side project "TransAtlantic" is getting ready to release their next album with 5.1 options.
Of the band's outside projects, I am only appreciate Rothery's "SRB" projects.