The other questions are how quickly you want to do it, and how you'll fit the study in with the rest of your life.
If you can take the time out to do an intensive course, (or even to do part of the course intensively) then you will progress much faster. I speak from experience having drawn my hang-gliding lessons out over many years, and having done my PPL in about 2 months. Progress can be very slow if you're having a lesson a month, and that gets cancelled 1/3 of the time due to weather or aircraft serviceability.
There's also quite a lot of bookwork to get through - none of it particularly hard, but reasonably time consuming and quite rewarding.