Face-to-face guitar lessons provide customized advice
When you take face-to-face guitar lessons, you are presented with customized information from an experienced guitar teacher. The material that you learn will be specifically tailored to your current ability. This alone is the best reason to take face-to-face guitar lessons.
If you really want to learn guitar quickly, my suggestion is to casually follow up on the stuff that your guitar teacher teaches you by doing a little online research each week, ten minutes maximum. Doing this ensures a greater amount of engagement with your teacher, and it makes your learning experience stronger and more meaningful. How?
Learning guitar online enriches what you are learning in lessons
Lets say that you are learning how to play Wild Horses by The Rolling Stones. Let's say that while you're learning the song you decide follow up and give it some context. You would discover that the song was recorded at Muscle Shoals, and there's also a wonderful documentary film on this studio. Researching who wrote what can also give the song, and the songwriting process, more context. Why not get into different ways to learn the guitar part? YouTube has a wealth of information on just this one song. Then, what if you brought all of this information back to your guitar teacher and inspired a new conversation?
This is learning guitar on steroids.
When you are more engaged what you are learning, your teacher automatically becomes more engaged in teaching you. Best of all, a quick ten minute search online can give you tons of information on just one song. My belief is that researching what you've learned in lessons will make your teacher far more excited to teach you. Just about everyone has had the experience of working with an inspiring teacher. Doing research like this just about guarantees it.