Yeah it's far more valuable getting private lessons (although they are more expensive of course).
My other advice is that if you want to improve dramatically at jazz, start learning how to play other people's solos. It doesn't have to be guitar solos of course but you'll find the guitar ones easier at first. Start easier with some Charlie Christian solos (his solo from Flying Home is a good example) and then move up to harder ones when you're ready (Wes Montgomery etc)
This in my mind is the single best way to improve your own jazz solos.
Becoming good at improv is all about listening and learning.
Miracle Blade 4: Gibs on touch.