But OP also says “my second priority is to be able to study a variety of subjects”, which makes one of his/her US choices a better option.
I thought you sort of flunked out of college when you first attended.
I made it to my senior year at UCSB. I graduated from Ventura Community College in two years. Did you know only 10% of students graduate in community college in California in two years? I’m not bragging, that’s just the facts.
When I transferred to UCSB I was doing OK for the first year, but then I got sick due to a disability I had from my military service. The second year I had to withdraw from classes while getting medical treatment. I didn’t withdraw from from my last two quarters and those grades turned to Fs.
It doesn’t really matter to me now because that was almost 15 years ago. My roommate who got a bachelors degree ended up becoming a massage therapist. A degree doesn’t guarantee a good job. I would consider getting a degree if I hadn’t spent so much money going to UCSB. Thankfully my MGI Bill covered a lot of it. I’m just thankful I’ve almost paid off my student loans.
UCSB turned out to be a much needed vacation, I learned a few things and I had a lot of fun. A lot of famous people went to UCSB and didn’t graduate, Gwyneth Paltrow is one of them.
I do wish that I could have skipped the general education requirements that American colleges require. The UK and Australian system seems much more reasonable to me. It would have been nice to jump right into studying one subject for three years.
@Broses - if you’re thinking about taking the Imperial offer, don’t worry about dealing with insane London rents. Imperial guarantees housing for your entire undergrad time as an international student. It may not be glamorous, but you have guaranteed reasonable cost housing if you need it while you’re there.
@PurpleTitan : Berkeley undergrad who chose it over Yale, Columbia and Cambridge, Warwick, UCL and Imperial College London. I’m on a Fulbright mission now. Will be going to MIT soon. 
Perhaps nothing compared to yours… But that’s not the point of this discussion. So, please let’s leave our resumes out of this.
I was only saying, Imperial College has ties with the tech industry, if that’s one of the OP’s concerns. And, I’d politely argue that what Imperial has in the tech industry is more special… and the ties it has with the tech industry are stronger… compared to what those other schools have in the OP’s other options. Of course, if he wants to better position itself in SV, going to school in America would make more sense. But those big tech companies in SV have major offices in London and those companies consider Imperial as a major recruitment ground. No offense meant, but I don’t think UCSD is regarded in the same exact way as how Imperial is regarded and viewed by those elite companies that you and I are probably thinking (Apple, Google, Facebook, etc.?) If we’re talking about Stanford and Berkeley, then it’s a different story.
If the OP is concerned about breaking into the financial and banking industry, he’s also going to give himself an edge if he’ll be carrying an Imperial qualification. Remember that Imperial is part of COWI - the top 4 unis in the UK for maths. None of his US school options is a top 10 program for maths.
Here’s the top 50 schools in the world for IB. Imperial is number 6 in the world. None of the schools in his list made it to the top 50.
1 London School of Economics 35.6% 2.5%
2 Columbia University 36.2% 1.40%
3 University of Pennsylvania 35.30% 0.9%
4 New York University 33.9% 1.6%
5 University College London 33.2% 1%
6 Imperial College London 33.2% 0.9%
7 University of Chicago 33.4% 0.70%
8 University of Oxford 33.30% 0.70%
9 University of California, Berkeley 33.30% 0.4%
10 Carnegie Mellon University
Okay, Berkeley is number 9. But you and I know UCSD is not UC Berkeley, and all the major employers know that as well.
@nollagam I’m not in traditional tech/software engineering and I wouldn’t dream of comparing resume girths, but I did want to point out that while UCSD doesn’t have as many “big tech” employees as Berkeley or Stanford, it does consistently fall into the top 10-12 for alumni at the major SV firms. It’s not a poorly regarded school around San Jose where I’m from.
@Broses, UCSD is not a commuter school, the campus just looks more dead on weekends because the majority of third and fourth years live and party off campus. The “socially dead” stereotype is a pretty widely mocked joke
Imperial is a just a much better school overall - now it depends on whether or not you want to be in London but it is likely to open more doors in the future
What math class are you in right now?
How interested in CS are you?
@nollagam & @ccfk1221, the OP is American. It’s not a matter of wanting to be in London. To find jobs, he’d most likely have to come back to the US because of work permit issues.
And yes, Imperial has a strong brand, but they would be studying 100% math at Imperial, which the OP evidently doesn’t want to do. Also, though numbers for IB look like raw numbers in which case no LAC would show up because they all are tiny.