I pretty much exclusively used the gold watering can, so my vote is for that one, but I can see the appeal for the silver! I just preferred the gold one since it could water more flowers, and I often watered my flowers. The longer animation never bothered me personally and I thought it was cute. I also became so used to it that I only remembered it had a longer watering animation from reading this thread lol.
I love using the silver tools (though those are the only ones I've unlocked), and the gold doesn't really fit the look I'm currently planning for my town