Intellectual for sure- but it needs to be a fit for a kid in many other ways besides rigor.
No Gen Eds- hooray! But for some kids, it’s those courses which actually become the “path” after college. No frequent quizzes to study for- fantastic! Except for some kids, it’s the regular assessment/feedback which keeps them on track academically. No (or limited) college organized social life- amazing! Except that means LOTS of time spent in local pubs which works for some, will be extremely unhealthy for others (especially for a kid who has struggled with substances already). Etc.
You really need a deep dive to make sure that all elements of the UK university experience will work for a particular kid. I know lots of kids who came home after their first year and the parents felt very burnt by the experience. Office of disability support? No, probably not. Dietician and nutritional counseling so that a kid with severe allergies can still maintain a healthy diet in the U’s cafeteria? Probably not. Academic counseling for a kid who made the wrong choice in terms of his/her program? No. Administrators to run interference with professors for a kid’s particular learning issues or challenges? Likely not.
Kid goes off to great fanfare (and the parents get bragging rights AND a lower pricetag than the US options) and then comes home after the first year to discover that they are NOT getting a year’s worth of academic credit at whatever place they are transferring to. Being on academic warning in the UK likely means a do-over back home. So the “we saved so much money” becomes paying 5 years for the Bachelor’s.
Great, fantastic, unbelievable option for some kids, terrible option for others. Any kid who has needed some sort of scaffolding in HS here (parental, ADHD coach, school provided intervention, substantial extra tutoring) may not be a great candidate for a UK university (at least for undergrad. By grad school the situation may look much better because the “growing up” part has already happened!!!)