That's incredible value, I currently pay about £60 per year for 60GB from sugar sync, mainly because of the seamless coordination from iPhone / iPad mac, which this MediaFire system seems to do.
Have you used it at all, or seen any reviews? The £60 for Sugarsync is worth it for it's functionality and ensuring my work stuff is properly backed up, but I'd switch in a shot if this MediaFire is as good.
So is there any catch