I totally agree with the earlier post: here in the States most of us don’t have lots of sessions with great players. We don’t have masters to sit next to and soak stuff up from. Even if we go to Willie Week or wherever, the other 51 weeks of the year we’re often on our own. That’s a lot of time to either make progress or get stuck.
Fortunately, we do have recordings. And Scoiltrad is great. But I still think there are points where you really ought to spend some human time with good players. For example: I figured I was intermediate/moderately advanced when I took a one-day workshop, my first of the sort, with John Skelton last spring. I knew a bunch of tunes, was able to get a reasonable sound, was able to keep up in a session, and was pretty comfortable with my flute overall. In fact, I thought I wasn’t half bad, if nothing else 'cause I could play really, really FAST. 
BUT. Even those few hours made me realize how completely clueless I was – especially about, as John says, “Making the listener say ‘What a great tune!’ instead of ‘What a good player.’” So now I drive about 3 hours round-trip for lessons with him (I’m lucky; there are people who drive 6 & 7), and the things I’m learning are amazing. I suppose you could call a lot of it nuance and theory (i.e., the finer points of the fling, how to vary a tune, forward -vs- backward rolls, finding the right feel for a tune, etc.), but there’s also a lot of “Hey! How do you do THAT?”
Bottom line: it really, really helps just to have someone in the know listen to you PLAY (and it sure beats just talking about playing
). After a while, they get to know your style, and they can help you avoid all kinds of pitfalls – if nothing else because they’ve already been through them themselves.
So while there are more than a few days when I miss being blissfully ignorant, overall I’m all for lessons, workshops, seminars, etc. – basically, I think we’d be crazy not to seize any chance we can get to play with/for people better than ourselves.
Okay, that’s it. Now I’m gonna take Sonja’s avatar advice again … 
Cheers!
cat.
P.S. Even if there’s no Irish flute player in someone’s area, I think beginners won’t hurt from a few lessons with a Boehm teacher – a good embouchure and good basics are a good embouchure and good basics no matter what kind of flute you’re playing.