I realise that sections of this post are answered in other threads but I feel a response formulated to a direct question will be more relevant.

I am currently on an LLB program at a former polytechnic in the UK, thus quite lowly rated (50-65 depending on where you look.As a side note I do realise that league tables don't mean an awful lot). I originally went to this institution on the basis of it being the best for another course. On successful completion of my 1st year I decided to change to my current course and am fully enjoying it.

Taking my considerations onto the possibility of studying an LLM.

From a few sources I am led to believe that excellent performance (1st class honours and top 5 in class or better etc) would leave me open to apply to Oxbridge and the like with offers being dependant on a well rounded application but not out the question.

My question comes with what I could take from an LLM, obviously with great performance and a good application I may well move to a very highly rated institution, somewhere I would have looked to go if I new I wanted to study a more traditional subject. If I was looking at moving to the Bar, traditionally full of oxbridge graduates, would an LLM proove very useful as

A:- I may have mastered a particular aspect of the Law which I then want to practice and
B:- I would then be a graduate of a more recognised Institution.

There may be many other benefits but away from academics, are Masters well regarded by employers?

I ask as I know big firms of Solicitors do not really care about Masters and place more emphasis on A levels and degree performance, but then they are more about knowing where to look for the law than knowing it (or so I am led to believe) and a Barrister by this theory would surely find a Masters very useful.
Thoughts welcome