Imperial College, what's it really like?

[amirrorimage]

Ideally I would prefer my DCs to make evidence-based decisions for their university choices rather than from whims and possibly unfounded rumours (most arising from classmates with no direct knowledge of places). I realise that I may be fighting a losing battle though.
Imperial College is a bit of a dilemma. My DC applied there for physics without going for an open day. Recently had interview (which did not go badly) liked the interviewer but put off for several reasons. The first is that the tutorial groups are of 20 facilitated by one senior academic and one PhD student. DC is from a state school with very large sixth form classes for the maths and science so would really like smaller tutorial groups at university (as well as good quality academic teaching of course)
The second reason ars the rumours about the lack of social life at Imperial backed by the interview group being almost all international students (with international sounding American accents).
Has anybody got anything positive or reassuring to say about IC?

I was chatting to my DS about this (cliques) as his GF is at Oxford and as he spends a couple of weekend there every month, he has seen both sides.
Apparently good banter at Oxford (the old " so, were you rejected from here or Cambridge?! ) and a good mix. Appreciated this will probably vary from college to college.
Echo what "amirrorimage* has said, no cliques at Imperial, some of the Asian students do speak Chinese to each other, but that's to be expected.
He's made some good International friends - lab partner is Russian
and of the other 4 female and male friends who he will be sharing a house with next year, only he and one other are UK based.