Good Morning M.!
What a blessed son you have! He has such an alert and caring mother watching over him!
All I can give you is my 36 years (and counting)as a person with "large tonsils". I can't tell you how many times my doctors, dentists, and orthodontist would make comments about my really big tonsils. (It has become a little annoying to me now when they bring it up!!) But I (like your son) have been blessed with very good health.
I used to snore pretty severely when I was younger, but after I got married and had kids the snoring has all but gone away. (I think between my husband there to remind me to "roll over" when we were first married, and my mommy ear always listening to make sure the kids are all right, I sleep lighter now.)
You mentioned the sound of his voice, and since I am a singer :-) I just wanted to give you a little something to think about. (Not that he is going to want to be on American Idol someday, or maybe he might?? Who knows??) A lot of how our speaking and singing voices sound have to do with how our throats, voice box, sinuses, and in general how our physiology is put together from the neck up. And tonsils are part of that unique physiology that we all have. I feel mine have helped my voice and helped me sing well so that I could perform solos and earn scholorships. Another singer I know felt her large tonsils kept her from singing her best, so she had them removed when she was in her 20's. Just another angle to concider in this issue.
I also have a 10 year old son who has been blessed with my large tonsils. For now they are not causing him any health or sleeping problems, so we have made the choice to let them be. Two thoughts I have in making my decision for him is 1. there is research that shows that individuals who still have their tonsils are less likely to get certain types of cancers later in life and 2. his body is going to begin growing soon, so if he grows and his tonsils stay the same, there may be no large tonsils in 5-10 years. Time will tell!
Good luck! You are on top of it, so I'm sure you will make the best decision for your son!
Peace,
B.