Mmm- tricky one. Especially if you both like the name- thats the hardest part- finding a name you BOTH like!! If it were me, and there was another name that my DH and I BOTH liked, then I would give the less common one preference- and perhaps use the common name as a middle name.
Or perhaps if there is another name that sounds similar but can easily be distinguished between the two?
Name crazes come in waves- so perhaps you could save that name for another bub down the track- when the name has died off a bit? Just a thought.....
If not... at least you have a name you both like. DH and I took forever to name DS1 as we stubbornly refused each others name choices!! My theory was- I push the baby out of my vagina- I get the last say!! Lol....