I don't think that there would be much difference, however, I would take the ABRSM qualification as it is more well known. I remember distinctly years ago when studying for grade 5 piano theory and practical with the London College of Music, there was a general opinion that the ABRSM was a harder qualification, personally I believe snobbery was involved. Maybe an idea, if you can be bothered, to have a look at the history of both.
Hope that helps and all the best with the studying!