Experience with cognitive behavioral and other therapy?

Hi. I've read that something called "cognitive-behavioral treatment" works for insomnia and am considering trying it myself. I am deciding between individual treatment and a group. I am curious if anyone has tried a group such as this one and can comment on her experience.

There is a group starting near me in Boston in December: http://calendar.boston.com/boston-ma/events/show/85314259-overcome-insomnia -group-therapy-treatment .

Have anyone have experience with this therapist?

Thanks.

-Sky