@diplodocus_ I have some similar admits! Also got into Stanford/MIT/Columbia, and rejected from Harvard (lol).
My impression is that Stanford's program is the most selective and probably the best for Silicon Valley tech. Personally, I'm also heavily considering MIT's MBAn because I prefer the east coast. I think the MBAn has a couple of other nice features that stand out, such as the 1) tight-knit cohort/sense of community and 2) great professional support. MIT's program also seems more applied than Stanford's program, if you have any preference on how theoretical v. applied the curriculum is. Another difference between these two schools that stands out is the length-- I do like that Stanford's program is a couple quarters longer and accommodates a summer internship.
Columbia is a great school for undergrad, but I have the impression that its Master's programs have very large cohorts, so there doesn't seem to be the same sense of community at the grad level. I also heard from a Columbia alum that the DSI classes are mostly night classes to help accommodate part-time students, if that affects your decision at all. On the other hand, if you want to be in NYC and develop a network there, Columbia should be fantastic for that.
Curious to hear your thoughts on Stanford/MIT/Columbia as well!