depends
AA V3 is a very different beast then CEP 2.1 some things will look familiar but conceptually it needs to be approached as a different application
the destructive edit section is still fairly close to the old CEP interface and in my experience it is still a very powerful and functional editor
With version 3 I find I'm using earlier Syntrillium versions less and less (until I picked up V3 beginning of summer I still used CE2K with some regularity, was a big fan of Syntrillium)
Don't have anything bad to say about Cubase, used some version of it almost as long as CEP/AA I don't think I'm upgraded since V4, have at least one version of LE . . . primarily keep it around for people who are comfortable with it
Not crazy about AA's hardware (control) integration for use with automation channels. Actually, for me, find those situations in which I just want closed eye pure fader control for automation that Cubase to be a little more functional.
Those these day's I'm using Reaper to track, frequently do a rough control surface fader mix in that as a reference then edit and mix in AA
good luck
