We did the two-day twos class several years ago. It's been quite a while, so I don't have super up-to-date information. We have other friends who send their kids through all three years there around the same time.
Overall, we liked the experience and thought it was a good school. You do need to be really involved because of the cooping requirement, but I'm sure you already know that. I liked having the chance to be in the classroom, especially for that first school experience for my kid.
One thing I didn't really like (but maybe it has changed?) was that my kid only had class 2 days a week and they were 2 days in a row. That meant a long time in between finishing one week and starting the next, so he got a little out of the routine. I think the 3-day or if they have a 5-day is a better option because of this.
The afternoon enrichment classes are also a good option, but I think they can't start until they turn 3 and may need to be potty trained to do those.