Also worth reading:
https://en.wikipedia.org/wiki/University_of_East_London#Rankings_and_reputation
UEL is actually highly regarded by many people who've attended it or otherwise know it. (I've worked in Stratford and I've spoken to many UEL students). However, like many former polytechnics, it struggles to get rid of its 'second class' reputation, meaning that the A-level grade averages of its intake are likely to be lower than those of, say, the 'Russell Group' universities (thus resulting in fewer First Class Honours degrees being awarded).
However a student with decent A-level grades (and a positive attitude to their studies) will probably do just as well at UEL as at a so-called 'good' university and, if they enjoy London life, possibly even better.