hi! I've looked into both for my possible uni applications although I'm not due to apply for a few years. Personally I've actually been to Sussex uni but haven't been to royal holloway. I do believe royal holloway ranks better in the league tables but both look pleasant. I don't think the accommodation at Sussex looks incredibly nice in comparison to royal holloway, but the last time I went to Sussex was about 2 years ago. if you're looking for a picturesque university, I'd accept royal holloway.