I'd suggest that you visit one of the LBS open evenings or Saturday sessions and interact with the student body. This would give you a picture of the demographic and whether you could fit in with the crowd. After all, much of B-school is filled with team-based activities.One point to note is that you are assessed on the total package, i.e. your undergrad grades, quality of work-ex, what you do outside of work, what you have achieved etc. Going to Aston, say, would not hold you back if you have a rich work-ex of leading teams and achieving great things in and outside work. Of course, you need to include the GMAT score in the package.All the best!