Autism Message Boards: Experience with floor time therapy?

My 3 1/2 year old son "C" has PDD-NOS. He was diagnosed at about twenty months old and we just received a waiver for therapy services through the WI Medicaid Program.

C has started traditional preschool two days a week and also attends exceptional education four days a week for speech therapy, occupational therapy and some physical therapy. We are leaning toward using the Medicaid therapy services which requires no less than 20 hours per week of therapy. The therapists offered throught the state are almost all ABA therapists but we do have an opportunity to hire a floor time therapist instead. We are somewhat unsure of pulling my son out of traditional preschool but feel it is probably best for him to get the 20 hours of therapy per week. Does anyone have any experience with floor-time for a PDD-NOS child versus ABA?