The nicest halls are definitely the newer ones (willow, juniper, beech) however they are very expensive. I think they are all en-suite rooms and shared kitchen unless you get a studio. Flats are generally 5 or 10 people. I have heard people say these flats are a bit more boring however I think it just depends on who you’re with.
I think there’s some newer ones at Alexander court but I don’t know much about them.
The other ones at Alexander court are decent too but a bit older. The flats that I’ve been in there I think we’re 6 people, shared bathroom and kitchen. The only thing with Ali court is that it is quite far from the rest of the campus about a 20 min walk from everywhere else but a lovely walk none the less.
The other accommodations are also older and vary between en-suite and shared bathrooms. When I lived on campus Andrew Stuart Hall (ash) was where a lot of people went to pres etc but there’s stuff going on in all the halls so probs depends on who your friends are.
Hope this helps!