i didnt apply to merton, but i had interviews there for classics. it seemed ok from my interviews i guess, but i was glad i ended up in the place i applied to, merton seemed a bit too uptight etc. (although i dont think i was ever likely to be offered a place at merton, i think it was more a comparing standards between colleges kinda thing because merton is ay more competitive than the college i chose, but anyway, i digress.)
anyway, it might be lovely, you can tell theres a lot of money there, and i wouldnt have minded spending four years there from what i said. go to some open days, theyre better than nothing.