Pros
Location: Northern Ireland is a beautiful place and Belfast as a city has improved a lot. Infrastructure: The university has some nice buildings, ranging from old architectural gems (Lanyon Building) to modern new buildings (like the ones behind the MBC on Lisburn Road). Dedicated and hard-working staff.
Cons
The management (at the university, faculty and school levels) is the weakest spot of this place. Beware especially if you are a new lecturer - at this university your career may go up in smoke before it has properly started. They will be happy to take you onboard and will promise you beautiful things. Make sure you get them all in writing, otherwise the chances are they won't materialise. The management will be happy to include you into the REF return (this is probably the primary reason why they got you) - your publications from your previous place of work is what they need. But the support you may get to develop your own research and lab there may be ridiculous compared to what you would get elsewhere. However, their demands on the output and grant income will be unrealistically high and out of touch with real life. All that counts is the grant money you can bring. Don't bother with investing too much time and energy into teaching - it doesn't count for much in the eyes of the bean counters sitting in the administrative building. The administration of research is painfully slow, so don't be surprised if it takes weeks or even months to arrange relatively straightforward matters. Tough luck if you have to explain this to your collaborators overseas. To paraphrase one of the previous reviews, at Queen's it means a lot who you know and who knows you. It is a small world in Northern Ireland and those who were born there either all know each other or are related to each other (or go to the same church - that too seems to play a role). Avoid if you can.