Girl Grey had hers out just after turning 5, on Valentine's Day, in fact. The hardest part for me was watching her go under anesthesia. That was traumatic. Other than that, make sure she gets adequate pain meds and don't be afraid to use them for the first day or two. Girl Grey did NOT want ice cream, surprisingly. She did well with soft scrambled eggs and shockingly, she wanted toast (and I think the hospital let her have it). I can't remember what else she ate--she preferred soft foods, but not cold ones. She was out of school for a week, but was feeling more like her old self by day 4 or 5.
All I know about tonsils I learned from Bill Cosby.
No first hand experience but a ton of clients who have had it done with absolutely no ill effects; I definitely second LG's recommendation to insist on good pain meds and be liberal with them for the first two days; pain management immediately after any kind of surgery is key for long term healing.
My nephew had them out a couple years ago and was a totally different kid after. Much healthier and a better eater- he used to just be sick all the time till they were out.