Quite often I read a comment thread, and then decide which comments I vote up. As soon as this is more than one comment, I get an error message that I can cast only one comment vote every 5 seconds. -- This happens quite frequently, while I don't remember ever having hit any other rate limitation of the site.
I think comment votes are quite useful to quickly find the important comments, and are rather used too little than too much. So wouldn't it be possible to make the comment vote rate limitation a bit more ergonomic, e.g. by setting only a maximum number of comment votes per minute, per hour or per day? -- Say, hitting a limit like 6 per minute or 60 per hour would already be much less likely.
Update (August 18, 2014): Now after two weeks, the score of this post suggests considerable interest in the matter, but nobody proposed anything concrete. Therefore let me make a few concrete proposals for polling -- see below. Vote up every proposal you support, and vote down every proposal you are against. Also feel free to add more alternatives. Depending on the outcome of this poll, I will make a concrete feature proposal.
Update (August 23, 2014): I just noticed that now the one-per-5-seconds-throttle for comment votes has been removed, as announced here two days ago. I thus think the main objective of this post has been reached, independent of this post. Unless people think otherwise and wish further changes, I therefore consider this case as closed.