As I understand it PD engineering is only available in Lboro or Strathclyde. I recall a thread where a poster was astonished that this was even a question, and obviously Strathclyde was better, but I was struck that that was a narrow attitude.
Strathclyde is in a big and popular city but that's not for everyone; some people would prefer a huge campus in a small town and the way that focuses student activity.
Glasgow is a long way away for a lot of people (I mean unless you live in Scotland or the north of England) which may be a factor (I’m very glad, for a range of reasons, that my DC were at relatively nearby unis).
It really depends on what you want from uni.
Liverpool: big city, very popular, lots of students, cheaper accommodation, NW location, close to coast
Loughborough: small town, huge campus, very campus-focused activity, amazing sport offer, cheap accomm, central in England
Bristol: Big city, very lively student city, not a campus uni, quite spread out across the city in terms of halls, student union, university buildings; accommodation very expensive, scenic location in SW close to pretty Bath and not far from the coast
Strathclyde I don’t know at all I’m afraid except to say it is in Glasgow where I have never been but people say it’s a great city. (I know the other three as I was at uni in Bristol, spent a lot of my time at Liverpool uni (both of those a while ago but geography is the same) and DS2 is at Lboro)