Newcastle is such a great place, I'd go there in an instant if it wasn't 6 hours away and people didn't stereotype me as a 'posh Southern b*tch'.
Seriously, though, I've only been to New'astle a coupla times but I loved it (and this is coming from a London lover). People are just so friendly and down to earth (in general), and you've all the benefits of a city, but not to the same colossal and sometimes overwhelming extent as found in London, for example.
When I went there a few months ago I bought a cappucino in Nero's, and the barrista was so nice that he gave me a loyalty card and stamped all of the boxes so that I could get a free coffee next time. You're probably wondering why I'm telling you this irrelevant story, but all I'm trying to say is that Newcastle is a lovely place itself and in terms of its people.
Unfortunately I have no idea about the Law courses - my insurance uni is Northumbria (which is sort of opposite Newcastle Uni) - so I know a bit about that, but nothing on Newcastle itself. And I've never been to Leeds, so... you know... I suppose I've spent 4 paragraphs saying what could be said in 5 seconds and is probably totally useless to you... but that's me I guess.
Anyway, I'd say Newcastle 100%. If I was me, I'd ignore me though. I'm tired.