Well, all the cassettes are 10-speed, so it makes sense that the more closely spaced the cogs, the more uniform and smoother the shifting. Whether it is noticeable with a properly turned derailleur? I doubt it. If it was a serious problem, you'd hear more about it.

I wouldn't let that sway your decision. Buy the cassette with the range you need, but don't obsess too much -- they are relatively cheap and you can always swap as needed.