There really is something to be said for playing with a REAL band, at least for a few years at the start of your career...

Thing is, an arranger is NEVER going to come up to you after the gig and go 'Hey man! I think you are rushing a bit on those slow tunes!'. It will happily sit there and let you murder the time, or the changes, or the structure, and you'll never KNOW you are doing it!