To be honest, there isn't a lot of difference between Kingston and Roehampton academically - both are 'newer' universities. The lecturers come from a wide variety of universities, both here and abroad. I can't say that I've heard anything about major scandals ...
In answer to your question about 'respect', it would be helpful to know exactly what you want to study. For example, Roehampton has recently been awarded a lot of money to establish a centre of excellence in human rights and citizenship, so those areas of its programme are very well respected. Equally, its education department has links with many universities here and abroad, and is very well known. As I'm not at Kingston, I honestly can't tell you much about there, although I know that their music and music technology departments are considered to be very good. As with all universities, both Roehampton and Kingston have areas of excellence and areas where they are not so good, so whether people will be impressed really does depend on what you study. However, in terms of rankings neither of these institutions is ranked particularly highly, and given the snobbery about universities (particularly on this board) this can be, in some people's eyes, a problem.
As for how the universities treat their students, well, that's a fairly subjective thing. I have friends at both Roehampton and Kingston, and tbh they all seem to have the same complaints about 'bad' aspects of the universities - not enough time with staff etc etc. Roehampton has a collegiate structure which adds a bit more of a community feel. It also has a fairly compact campus so you're never too far away from anything. One of the complaints I've heard about Kingston is that because it has quite a few campuses and residences spread about the town, it sometimes feels like it doesn't have much of a sense of being one university. However, I suppose how you feel about this depends on what you're looking for from your time at university. Obviously if you're not planning to live on campus then the 'community' might be less important to you.
Since you don't live too far away from either of these places, I really would suggest that you go and have a look around the campuses, go to the open days and make your own mind up. I think there's a Roehampton open day fairly soon.
Hope this helps!