My thoughts on the Collegio...

Living as an ex-patriot has many benefits and a few downsides. One of the many benefits is learning a new language, being immersed in a different culture and having a housekeeper for eight hours a day for about $15.
Some of the downsides are not learning the language fast enough and realizing that even a pre-schooler can go to the grocery store and clearly ask for what they want in Spanish, and you can't.
Another downside- when any issue arises here, the severity of it tends to become inflated and magnified, simply because of living in Colombia.
For example, there is an ongoing discussion about which bi-lingual school is better here, the Colombian school that follows the British system or the Colombian school that follows the American system. As far as I am concerned, they are both good Colombian schools. Each offer a bilingual education where about 30% of the instruction is in Spanish and the rest in English. For me, I chose the Colombian school that follows the American system because my children are older and are already used to that system. 
My priority for them is to learn Spanish.  Some parents here are worried about how "behind" their children will be when they return to the States. My answer to that is, 'How behind were they when they got here?' Not all school systems are the same in the US, some are ahead in math and science and some woefully behind. I find it interesting that some people feel entitled to a US education even when not in the US (but that is another blog post, yet to be written about the entitled attitude among some). 
The benefits for children from the US to be exposed to another culture and language far outweigh any negative aspects to the education here.  If I find that my children have fallen behind on either math or science, it is an easy enough remedy, tutoring and in a month or two, they will be right where they need to be.
I have found my children's school to be engaging and responsive to any questions I have had since coming here. The school also has a much richer arts program than any of the US schools my children have attended. They not only get music and art but also drama. Their art and music classes are well equipped and extremely creative.
My son will be in a play in his drama class and his part is entirely in Spanish! He invited me to go and said, "Mom, you can go to the play, but it's all in Spanish, you won't understand any of it."
While that is true, I probably won't understand it, the important thing is, he is learning so much from that experience. My children both take Spanish as a Second Language (SSL) classes everyday.
They are now teaching me how to say words and phrases in Spanish.