T.L.
Yes, my son was 2 1/2 when we did the sleep study. He too had enlarged (giant) tonsills due to repeated infections. The sleep study was tuff to attend and go threw. (NOT at the location your going to) wanted me in way past his bed time (10ish) and they wake you way too early (5ish). The sleep study did not come out with the results that I expected. His sleep apnea in my opinion was much worse at home than at there. He ended up having both his tonsills and adnoids removed last August. He now eats and sleeps much better. Previously he woke up at least 7 times a night or more. He had never slept through the night either. He would spit all his food out after chewing it for more then 5 mins.
Here is a link to more info about it:
http://www.aap.org/publiced/BR_TonsilsAdenoid.htm
Good luck,
TL