I really love both Rufus and Reuven, really no idea which I prefer. I love the nickname Roo or think Rufi is cute for a baby/toddler too but the nicknames seem to work with either name.
Reuven is I think fairly uncommon in the UK whilst Rufus is certainly more known which makes me think Rufus. But then maybe that means people are more likely to have negative connotations around Rufus?
Really I can't decide between the two! Which would you go for?