Hi,
I will take IELTS in the coming months. I am planning to apply to UK universities, most of which require 7 or 7.5 band and 7.5 in writing.

My question is, is it really enough to meet the minimum requirements or would it better to make it an 8 band in the test?
Does the difference in IELTS score between 7.0 band to 8.0 band make a difference in evaluating the candidates?
If not, is it really the motivation letter, recommendation letter and the GPA which makes the difference and not the IELTS score?
Thank you.

It does not make any differences in the admission evaluation. Academic merit basis is the main consideration in most of UK universities. However, most of the candidates score in excess of the minimum requirement although it is not compulsory. Other documents such as motivation letter and recommendation letter are the supplementary factor to enhance the chance of your application. Depending on each college, some place provide a pre-session course to strengthen your academic writing skill. It is best to check your prospective university’s website. You should do your best. The writing band score is the most important. Many candidates failed to score the writing band exceeding the minimum required mark. 

I have seen the IELTS be the determining factor in an application. You never want to apply with a minimum requirement, however just .5 extra on the adults is enough. The work that you have done in your undergraduate, any internships or externships, volunteer work and how you have developed your CV will make the biggest difference in the law school application. In addition, it is good to increase your language level above the minimum requirement. Studying for the test can be beneficial to stimulate your brain, and learn new things.