You may find a higher number of rentals in Milwood/Hunter's Chase - thus a somewhat transient population and also I don't think the homes are kept up as much as other neighborhoods. I always feel like those houses over there need a coat of paint! Milwood was built by Milburn Homes - a no-frills builder and I think that shows. I personally wouldn't choose Milwood simply based on the quality of the houses, but they do have a nice park and there seem to be a lot of kids in the area and it's in a convenient location - closer to Austin than the other areas you mentioned.
Lakeline Oaks is nice, but I much prefer Forest Oaks. I think Forest Oaks is the most upscale of the neighborhoods you've listed. Cat Hollow has lots and lots of families/kids, etc. but they've been building in that area for 20+ years, so there is a huge variety of age/look/size/quality of home. If you want a more homogenous look/feel, you'd like Lakeline Oaks or Forest Oaks better.
All of the areas you speak of have good schools. My daughter is in RRISD PPCD and I feel that their special needs preschool is very well run. The assessments are done at Brushy Creek Elem. I don't know anything about Leander ISD special ed.
I did look up some info for you regarding the schools you mentioned though.
(First number is # of students, second is student-to-teacher ratio, third is TAKS score out of 200)
POND SPRINGS: 773, 13.8, 191.0
NAUMANN: 875, 14.3, 189.0
COX: 731, 14.6, 189.3
GREAT OAKS: 1028, 16.8, 197.3 (wow...big school..that's a lot of kids!)
BRUSHY CREEK: 769, 14.4, 193.3
The numbers of kids at Naumann and Great Oaks seem like a lot, but you probably can't go wrong with any of these schools.
PPCD is 4 hours - starts at either 745a or 945a - you'll be assigned to one of those.
From the RRISD website regarding kindergarten:
(
Round Rock Independent School District - Elementary Education)
"Any child who will be 5 years old on or before September 1 and who lives in the Round Rock ISD is eligible to attend the district's full-day kindergarten. ..............A half-day prekindergarten program is also available for children who will be 4 years old on or before September 1 and who live in the district and have a limited ability to speak and/or comprehend the English language, are homeless, or whose family income allows the child to qualify for free and reduced lunch."
So...kindergarten is full day, and the district is very strict on not allowing any child who is not 5 on Sept 1 to go to kindergarten. If your birthday is Sept 2...you're gonna have to wait!
I think that's all I know!