Q:

Can we please allow changing votes?

The rationale behind locking in votes is to prevent "tactical downvoting" - more specifically, to prevent people from getting their reputation back after downvoting.
However, this comes at a huge cost: If I find an answer that seems to work and upvote it, only to discover an hour later that it is an ugly hack that terribly breaks something in a subtle way, I cannot downvote it anymore. Here's an example.
Can we please get this fixed? Not "refunding" the reputation for downvotes once the lock-in time has passed would achieve the desired goal without preventing the legitimate use cases. (Please make sure reputation for downvotes only deducted once if the same answer is repeatedly up- and downvoted).
Also, it has been correctly pointed out in the comments on the meta thread linked above that the reputation hit taken by tactical downvoting is insignificant. If someone doing it downvotes 4 answers and gains one additional upvote through it, he's made "profit" even with this protection system in place. Thus, it may be easier to just drop the lock-in.

A:

The solution is to wait before voting.
Do your testing before voting and only vote when you are sure the answer is helpful or not helpful.
If you down-vote, remove that vote and then reapply it (assuming it's within the 5 minute window or the post as been edited) then you will lose 1 reputation point, get it back and then lose it again. There is only a cost of 1 point per down-vote on an answer.
If, despite waiting, you find a flaw with the answer later then you can edit the post and change your vote. It is allowed. Though it might be more constructive to leave a comment explaining the flaw and why it's a big problem - the answerer may be able to fix it. It would be even better if you could fix the answer yourself.

