Hi Michael,
I don't see myself using it much but Studio One seems awesomely smooth and easy. It seems like it's fun for jamming. I had the Artist version on my laptop and used it too manage some practice files and record dubs of guitar jams.
I'm looking forward to trying out it's *mastering* layout for assembling collections.
If you want to use Spectasonics you should probably steer clear of PT11 until there is a 64bit AAX port for the synth.
If you were to go with PT you might want to grab the combo PT 10.36 32bit/with upgrade to PT 11 (x64) that has been available as a limited time offer. 10.36 will run the RTAS.
SONAR 8.5 is running great on my new system, but I am daily reminded that every bug in it is in it for ever.
best regards,
mike