I'm currently in a DBT group and I continue to see my regular T as well. My regular T is familiar with DBT, but not trained in it like the therapists who lead my DBT group. The place where I go for DBT it totally fine with me continuing to see my regular therapist, but I guess that could depend on the place. DBT has been helpful for me, but I agree it might not be the "magic bullet" for all problems. I do think; however, at least from my experience, it is worth a try. In my opinion a lot of the concepts from DBT could benefit pretty much anyone. I would ask your T and the place where you will be doing DBT about things like the length of time you are expected to commit to the group, and if you can continue to see your current T. I would ask them to give you a straight answer so that you can make the decision that is best for you. Take care.