D.W.
My oldest started kindergarten this fall at the Richfield Dual Language School and we've had a great experience so far! Overall things have gone very well and she's picking up a lot of vocabulary with each unit. RDLS is a little different than many immersion programs in that half of the students are native Spanish speakers and half are native English speakers, and their model is that things start out 90% in Spanish and 10% in English and will gradually transition to 50/50 by 5th grade. The idea is that the kids will help each other out and learn from each other along the way, and in our experience this does happen and it enriches the learning process for our daughter.
It's definitely a choice to commit to, though! I wouldn't say we've had any "negatives" per se but there are some different things that come up in an immersion program that might not in regular school. Our daughter was totally exhausted for the first couple of weeks, and she was a little frustrated that she couldn't understand what her teacher was saying most of the time. Her teacher is very demonstrative, though, and so of course she did understand when it was time to go to lunch, for example. We talked with her about how it was new for a lot of the kids and that it was okay that she was still learning, and that she would start to understand more and more of what her teacher was saying. She started to realize that she was picking up a lot of the meaning behind his words even if she couldn't exactly follow everything. 4 months into the year now, she doesn't complain about that anymore and just focuses on trying to pick up a few new words at a time. Most of her homework comes home with instructions in both English and Spanish, but a couple of times the instructions were only in Spanish and we just had to do our best to figure it out. Our daughter still is at a point where she understands much more than she can express in Spanish, so sometimes homework is challenging if she needs to, say, write a sentence about what she saw on a field trip. Again, though, I don't know that these things are "negatives" so much as they're added challenges to overcome now in exchange for added benefits later, if that makes sense.
I hope this helps, and feel free to e-mail me separately if you'd like to "chat" more about it!
Sara