Seems like I'm a minority.
I send DD7 to Kindergarten- at 4. her birthday is mid october, and I wanted her to go early. District cut-off is Sept 5th, but I lobbied for her to go early. She was tested and went early.
They have full day kindergarten here as well. She did exceptionally well, as did DD8 who went at 5, with a June birthday
I think you need to remember, that kindergarten NOW is not what kindergarten was back when we went. They no longer spend the day "playing"...its completely different. Heck- my DD's were reading at late 1st grade level at the end of kindergarten, because of the educational program in kindergarten. Dont get me wrong- they still play A LOT, but its a lot less than they ever did before.
I think all day kindergarten is a wonderful thing. oh- and here they go from 810 to 240
Brandy