I kinda like the delay, but I could see not all would. It's strangely fun waiting in anticipation to see (about) how much of a difference your upvote made.

Generally the faster the better though! Not too long ago upvoting would simply turn the circle green instantly, and would pretty much send the transaction instantly too. I wonder if people upvoting and quickly navigating away caused vote transactions not to be signed. I have noticed that after the spin animation was added if I vote then navigate away while it still spins, the vote has gone through, so there's probably some slack in the time to show you the (now) blue-filled circle and update the pending payout total.