The problem with the arcade version, to me, is that flapping is a chore. The birds are too heavy. Sure, I guess it adds a bit of challenge to the experience, but it isn't as fun. In the 7800 (and I assume the Atari 8-bit) version, the birds feel lighter. You're free to concentrate on what you're going to do next without worrying about flapping finger fatigue. Or thumb fatigue, of course, but it isn't as alliterative. And I've never been a fan of the way the birds look when on the ground in the arcade version.