I think that the value of lessons will be dependent upon your teacher and your relationship with them. A good teacher can help develop your style whilst showing you the quickest way from A to B, avoiding "bad technique" that is limiting speed etc.

I have been playing for 20+ years and took 6 months worth of lessons (for the first time) about 3 years ago. It was quite a rewarding experience and taught me the basics of music theory. Some of this has been helpful!

However a bad teacher... bin them fast !

Me, well... having got the modes and various minor scales down, I will expand my chord vocabulary and finally learn to read music via multi octave arpeggios. I am starting to expand my tapping also and that is an area I want to spend some time on. I can do most of this with a book however, if I manage to find a good teacher, I can just speed it up a bit ! (bad pun I know !)