I worked at a Day Treatment high school for over two years.
I don’t know how comparable the experience would be.
Generally speaking, adolescents in Day Treatment have more severe psychiatric issues and the consequences of their behavior are far more serious than the pre-school and elementary programs that I have consulted/visited. The reasons for student placement are far more extreme than a lack of good early intervention.
By nature, preschools and elementary schools are much smaller.
Although generally a good thing, the negative of smaller size is a lack of capacity and resources increasing the likelihood that they will refer out to another program.
The younger you go, the more likely that the day treatment provides successful early intervention.
As previously stated, individual quality matters.
Also, once successful exit criteria are met, the transition and the step-down process are the most critical steps in preventing a need to return.