Go to a UK uni if you are only interested in 1 major. Go to a US uni if you're not sure where your interests really lie and wish to be allowed time to explore and ultimately end up with a double/triple/multiple major.
There are around 3000 unis in the US. MIT is top-notch. You might be interested to know too that MIT is ranked higher than Cambridge by the most recent THES rankings
(a British publication), the very same rankings that placed dear UM at 169.
People want to go to top schs like MIT simply because they are the top. Look at the THES rankings
again, 12 of the top 20 are in the US. How many from UK? A measly 4. The US has been outstripping UK in terms of education for quite some time now. Harvard perenially hogs the numero uno spot on most respected publications.
(IMO, most rankings are flawed to a certain extent. But it's the closest we have to what can be passed of as fact.)
If you get good enough grades on the STPM, schs may allow you to skip up to one year of study cos it is true that first year college work is about equivalent to the stuff learnt in the STPM. But that's cos college-bound kids in the US would only have had 11 yrs of schooling prior to college. In contratst STPM students have had 12/13 years of sch. An advantage in being able to skip the first yr of sch is that you can complete your Bachelor's in 3 yrs and get your Masters in your final yr.
NUS is just not in the same league as either MIT or Cambridge.