Interesting questions oh Wise Man! You can count me in on your long list of Berklee drop-outs! I went for 5 semsters, got my self to where I could function at a professional level and split. It wasn't until I went back to school 11 years later that I finished up my bachelor's and went on to get my Masters.
Well, my observation has been that the players that are going to make, are going to make it no matter what or where. When John Myung was my student at Berklee (okay, I'm name dropping!) he never did what I asked him to do, he'd come in and say "I don't need scales and arpeggios because I have a band and we're going to become big." I thought, "yeah, I've heard THAT before!" Well, I'm glad to see that he was right! The funny thing is take a look at his instructional video, what does it say on the cover? - scales and arpeggios! Maybe an impression was made without me knowing it. Anyway, most of the guys I've taught that went on to do things came in with something happening already, even if it was in a raw state. I was like that as a student too. If you ask any of my old Berklee teachers, they'll tell you I wasn't the best student, I had the classic "I don't need to do this" attitude. Of course many years later I found out they were right!
To get back to your question:What's the best way to get the education?
It reeally depends on you, your resources at hand and your learning style. Ultimately it's you that does the learning, so as long as you have the willingness to do the work, you'll get it through whatever means you can. It also depends on your goal. If you want to do gigs in jazz or pop, maybe all you need is to have your skills together enough to cover the gig. If you want a symphony gig, you better stick it out as the paper is just as important as how you play. If you want to teach at a college level, graduate work is a necessity.