Hi there,
I studied English Literature at Glasgow University and although I went elsewhere for my MLitt, I have plenty of friends who studied on the various MLitt programmes there too.
In short, I had an amazing time at Glasgow University and this was mostly due to how much I enjoyed the course and the English Literature department. I know how different MLitt study is to undergraduate so I will try and raise points which will be relevant for your stage.
I know that Glasgow does have a very good reputation for English Literature overall. Throughout my four years the staff were extremely knowledgeable. Most, if not all, seem to be publishing regularly and highly regarded within their respective fields. Lectures and tutorials were almost always super informative, well structured and stimulating. I had essentially no bad experiences with staff ever and a number of staff were particularly helpful when it came to essays, dissertation and supporting me with decisions on postgraduate options. They were quick to reply to emails, happy to discuss things with you in office hours and were open about pointing you in the direction of resources, etc for essays. This view was widely shared by a lot of my peers too.
In terms of the focus thematically, in my experience there was quite a large focus on Victorian/Romantic period with a number of staff specialising in this and then another heavy focus on Modernities and Literary Theory with another branch of the staff. I am not sure what MLitt you are doing but in my memory the Victorian Literature one and the Modernities one were particularly popular for this reason. I have two friends who did Modernities and both had excellent experiences. I see above you mentioned the Fantasy course too, Rob Maslen, the convenor of this course, taught me at undergraduate level and he's amazing. I've never met such a committed, enthusiastic and knowledgeable teacher. I know he is active on Twitter and I am sure he'd chat to you about the course if it is one you were interested in. I honestly love the department.
In terms of the campus, Glasgow University really is as a beautiful as everyone says. The old building is probably the main feature you have seen. However, the English Literature building, on University Gardens, is also very cute - like two old houses - where most of the staff have their offices and tutorials will be held at Masters level. It's all very picturesque and feels much older and more 'old school' like. But then you have the beauty of being in a bustling part of the city and not far from the city centre, in fact.
Ultimately though, I would say, go where the course interests you the most and where your particular area of research matters. For example, my focus was on Scottish Literature so although I loved Glasgow and the English department there, I ended up doing my MLitt at Stirling because the Masters in Scottish Literature there is the only one of its kind. Although I liked the university less, I really wanted to do that course and so that determined my decision. I think this was ultimately the right option. For example, I know I wouldn't have had as good an experience if I had gone to do the Modernities MLitt just because it was at Glasgow because the subject matter wouldn't have been right for me.
I hope this helps and good luck with your decision!
Lilith