In our house, all of the various bathroom sinks and showers have two handles, while the kitchen sink has a single lever. With two handles, changing the temperature of the combined water flow changes the volume, so it always takes a few more seconds of fiddling around to get everything right. On the other hand, the single lever is intuitive, faster, and only requires one hand. That's a definite advantage whether you have something in one of your hands -- like a toothbrush or bar of soap -- or not.

I would probably go with a remote sensor faucet instead, the kind that turns on automatically when your hands get close to it. It stays clean and obviously no germs issue (I'm not a germophobe, but I've always despised sink faucets with round-ish knobs. I know everyone's hands aren't clean when they turn it on - that's why you're washing your hands in the first place - but you have to grasp a dirty knob to shut it off. 1/4-turn lever-type handles, or single-handle faucets where you lift the lever to turn on, push down to turn off are much better, since at least I can push the lever with the back of my hand to turn water off, and the front or top of the lever in theory should be relatively clean.)

natal, thanks for the photo. It really helps since I wasn't able to visualize it, and it's good to hear that the positioning has an up-side as well. melissastar, I had been thinking about an angle installation so it's helpful to know that worked for you and quickly seemed natural. Thanks to both of you for responding with helpful info!

I think numbers is correct, which is why I still have the awful antique brass with smoke acrylic knobs in all three of my bathrooms. I'm don't want to update all those fixtures until I'm ready to gut them all :/