FWIW, here are my thoughts. (Context: I attended UCSB for 2 years in the 80s but then transferred. My sister and brother in law are both graduates. Santa Barbara is probably my favorite place on earth. And my daughter is currently deciding between Northeastern and USC, which also has a higher ranking than NEU.)
I don’t think 30 v 49 is significant given how many colleges there are in the U.S. Also, I have read that NEU’s ranking is lower than some because of the number of students that take longer than 4 years to graduate. But that is largely due to co-ops, where they are getting real-life experience, not paying tuition during that time, and many are earning money.
As you note, the campus culture/location probably couldn’t be more different. UCSB is always on the list of top party schools. But it’s not a “spirit school” like UCLA. They have sports, but it’s not a big part of the culture. (Things may have changed, but there were no tailgates in my day.) Same for Greek life: it’s there, but not prevalent. Also, the campus is not in Santa Barbara. It’s about 10 miles north of Santa Barbara. So you need a car or to take a bus into town. Students don’t spend a lot of time there. Most of campus life surrounds Isla Vista, which is an an unincorporated community adjoining the university. It has a storied past. But now is home to most of the (extremely expensive) beach front/adjacent off-campus housing and maintains a hippie vibe. It is also party central. A bike is a near necessity.
As far as the education goes, UCSB (and all of the UCs) are grounded in theory. They teach students how to think and prepare them for graduate school. There are many large lecture classes where most of the interaction is with a graduate student. Most classes are not practical but rather encourage “deep thinking.” (That said, UCSB does have a writing program of some note, but I’m not familiar with the details.) Personally, that was the reason I transferred to Cal Poly SLO. I wanted to study business and UCSB offered “business economics,” which was very theoretical. I wanted to study, finance, marketing, human resources, etc. I also wanted to be employed right after graduation. NEU’s experiential learning model reminds me of Cal Poly’s “learn by doing” philosophy. Except NEU has all of the resources of Boston.
They are both great schools. So I think it really is a matter of personal preference, both in culture and type of education. (Not helpful, I know, especially when you can’t visit. We are having the same issue with NEU v USC. Although thankfully we visited NEU pre-COVID. Good luck!)