What I've been finding is that it's pretty issue to replicate the look of 2 weeks after a professional haircut (overall a good length, nothing that would be noticeable in public, but not as neat and crisp as you'd want for a formal event).
This "OK, but not great" look takes literally 5 minutes - a quick sweep over the whole head with the long #12 guard, cleaning up the area around the ears and neck with a #8 and trimming the beard with a #4. I could easily go for months (or years) like this, but think I might still like the occasional "real" haircut when (if) this is all over.