I've been reading Chaim Potok's "The Chosen" and it got me thinking of Reuven (which is the narrator's name). I rather like it, more so than Reuben, possibly because the latter has contains the somewhat unpleasant "rub" sound.
I just suggested Reuven to a pregnant friend the other day. I love it. I never liked the Reuben variant because it made me think only of the sandwich. But Reuven allows me to enjoy that earthy "roo-" sound without getting hungry. :-)
This would be the usual pronunciation in Israel, of course. It's like Dvora vs Deborah or Aviya (for example), a modern Hebrew girl's name but a male name in the Bible, where it appears as Abijah.