The problem for us in doing the CTY math is that it feels like a "bridge to nowhere."  I'm not sure I want my son to do third grade math in 3 months, then 4th grade, then 5th grade...  It looks boring too to do all of that repetition.  We are doing a little bit out of a few math workbooks daily, which works for us.  The CTY courses are also very expensive- like $800 for one course for 3 months.
  He can take courses for gifted children at our local community college in the summer, but not until next year.  Grrr!!  I'm scrambling to find things again for this summer.