It really depends what you are looking for - I can only answer accurately from our experience as opposed to hearsay about other schools.
Our oldest (starting college in August) was VERY difficult to place - went to Stargate for 4 years....Stargate is an ACCERATED school, NOT a GIFTED school. RMS was our savior school for 4 years. High School was a disaster - tried 2 different ones and then he ended up failing out (he already had a high school curriculum at RMS) and took his GED last year. Failed out of high school, but aced the GED....

Our youngest....every different creature....more well rounded, extremely social, loves sports and VERY adaptable. He went to RMS for grades 1-5 and will start at Dawson for 6th grade this fall which seems like a good fit for him.

Other good schools...lots of former RMS parents are homeschooling, many are trying the public middle schools this year in Boulder County. For elementary some are going to Niwot Elem., BCSIS, Boulder Country Day. For middle, many RMS kids are going to Summit, Manhatten Middle, Boulder Country Day.
Hope this helps.....