If I had the money and wanted a particular rack for a conversation piece or to just stare at (like the John Breen buck) then yes, I would buy repro's as long as they were good.
This might sound like a plug (hopefully I've been around long enough for it not to sound like one) but a friend of mine has been working with an antler reproducer that puts out top notch stuff. I've handled his repro's and his 'competitors' and his antlers are quality. Most of the repro's are a little rubbery feeling but this guy's repro's feel like solid bone. I've held his originals and repro's side by side and couldn't tell the difference between the two (until I knew what to look for, but even then it was minute)......I mean the coloration and weight were damn near exact matches! I've even rattled with his repro's and they sound authentic. Again, if I was going for authentic looking/feeling antlers I would buy a set. And as far as rattling is going, I honestly can't see buying a set when I have already or can find a good set. But if I had the money and wanted the "real" thing then I would buy a set for a mount. Just my $.02 of rambling.