I graduated from Duke, while my daughter is soon to graduate from Rice.
Duke had/has a very frat-centric, pre-professional vibe. As an independent and a humanities major, I felt fairly alienated from the main flow of campus life during my time there–though I was hardly alone in that feeling. If you are a gregarious and fairly conventional “joiner” who is already thinking about how to parlay an engineering degree into an IB gig and then a spot with a venture capital firm, you’ll probably love Duke. If, on the other hand, you are looking for a place to undertake a process of intellectual and personal self-discovery, you might well find that Duke is not a good fit.
Based on [what I know of] my daughter’s experience at Rice, I would say that this school does of much better job of integrating a diverse array of personality types into a shared social and academic community. The residential college system is key in this regard, for it makes possible a rich social life (including lots of public, open-to-all parties) that is not weighed down by the elements of exclusivity and exclusion that can mark Greek-focused campuses like Duke. If you think of yourself as being even the slightest bit quirky or introverted, I would say that Rice is much more likely to provide you with “an active social scene.”
As for school spirit, consider this: I knew many people at Duke who, for one reason or another, didn’t really like being there or didn’t really identify with the school (even though they might root for the Blue Devils come ACC Tournament time). At Rice, by contrast, virtually everyone my daughter knows identifies with the school and feels a part of the Rice community . . . even if they don’t show up for football games on Saturday afternoons.
In sum, Duke can be a good launching pad for the right kind of student; however, I think there are many other students who would be well served by giving Rice serious consideration as an alternative. Good luck in your deliberations and applications!