I'm an academic and have been Admissions Tutor for two big, popular science departments at a smaller university and a larger 1994 group university.
I had up to 800 UCAS forms some years and there is no way I could ever read even a small fraction of the personal statements. I had an admin person triage them by predicted grades, and then made offers based on those, reading the predictions more carefully in borderline cases.
Near misses DO depend on everyone else's grades but it was rare that I couldn't take at least some people who had a near miss. I also took into account the subjects (for example, we did not require A or AS Maths but found it very helpful for our students so if we had 10 places to give to Near Miss students and 30 with the same points but 10 of them had A level Maths we'd take those ones).
We read personal statements carefully for "mature" students but not to trip them up - more to get an idea of whether they knew what the course was about and to help understand their situation e.g. when was each part of their study, did they do A levels at school and then not study for 20 years, or did they leave with GCSEs and just spend two years out before doing an access course.
And some of the criteria (ie. research funding to that Dept or 'how many journal articles each Professor wrote last year') will have NO bearing on the 'quality' of the course or the Uni.
Not necessarily true. Staff:student ratios tend to be associated with "quality" of research, and committed researchers have a passion for their research and want to pass that on to students. Students will learn more about the meerkats of outer Mongolia or symbolism in Winnie the Pooh from a specialist who spends their life being a geek about those topics, but they will also learn the latest on meerkats and symbolism in general from someone who is an active researcher on those topics, than someone who hasn't really done much research since their own PhD 20 years ago.
Don't apply on the basis that you MUST be taught the specialist module on meerkats, though, as the lecturer whose specialism it is may be off in Outer Mongolia on sabbatical when you get to 3rd year. And the league tables themselves are probably not that helpful (at least, beyond "top third" etc.) because the universities will publicise the one out of 10 tables where they are in the top 10.
But in general, more research active staff will be more up to date. It is worth checking the department has a general good spread of expertise e.g. if going for Geography, that there are not 25 research stars in physical geography and 5 new lecturers in human geography, which implies that human geography is taught by non-experts who are overworked, and physical geography teaching is not usually taught by the professors because they are too busy and important (I didn't apply for jobs in departments like this where I would have been in the human geography equivalent, because I knew I'd be stretched thin on teaching and have no time to do research).