Just looked at the new location in Takoma Park today and am heavily considering signing my 3.5 yr old twins into this program next week. It looked great and the program director was super accommodating and friendly when I decided to pop in on zero notice to tour the facility.
She mentioned that the principal for TPES does have her child in one of the classes. Several of the school teachers' kids are also in this program.
I haven't seen the SS location, but this one was clean, tidy and looked just like a normal elementary school classroom. I guess it helps that they are located in the new wing that was completed during the renovation of TPES.