the switch, either air or fiberoptic, is not hooked up in any way to the disposer. It is plugged into the disposer outlet, and then the disposer is plugged into the outlet on the switch outlet box. so you can use this switch with any appliance that plugs into the wall. I added a picture of cheap one I found on amazon. You can see that there is a cord that plugs into a regular outlet, and a box with two other outlet receptacles on it that you will plug your disposer into. there is a length of tubing, and a button that gets installed on the countertop. if the switch stops working: 1. check that it is plugged in 2. check that the GFCI did not trip 3. check the plastic tubing to make sure it is secure 4. unscrew the button from the counter top and clean it it is a very simple device and is worth $20 at most. Just buy the cheapest one you can find in the finish you want. a homeowner can easily replace it. the fiberoptic ones just use a touch sensitive pad rather than a mechanical air switch but install the same way and fit into the same size hole. these cost about $75.

Home Depot carries Insinkerator air switches. If you go, make sure you ask for a "SinkTop Switch" or "Top Switch" and not an "Air Switch". I asked for an air switch and not a single person knew what I was talking about. I found them myself next to the garbage disposals. They were $62, including tax. I bought my Insinkerator air switch on ebay, for $50, including shipping. It came in a package with satin nickel, chrome, and white buttons. I got the satin nickel to match my stainless faucet. Looks perfect! Here is a link that might be useful: Insinkerator SinkTop Switches

I considered the fiber optic switch, but opted for the air switch. Given that I wanted the button next to the faucet on the granite, the pivotal reason was that my fabricator can't really drill a hole smaller than the size used for soap dispensers and air switches. The fiber optic switch is smaller, but it still needs a housing to "plug" the unnecessarily large hole in the granite. And it costs significantly more. As to installing an air switch on a vertical surface: why not? As long as you can thread your tubing from the push button location to the power module, it should work regardless of the orientation of the button. See gnancy's diagram.

I have the Waterstone Traditional PLP at my main sink (LOVE IT!) along with the hot/cold faucet and a a soap dispenser. I have a 36" sink and it isn't crowded at all. Plenty of room to add an air switch and another dispenser for lotion. I also bought an air switch for the garbage disposal but ended up not using it and stayed with the wall switch. My reason for doing that had to do with safety after watching my daughter playing with every button and knob when we were in at a store. It looked like something fun for her to play with. The wall switch doesn't give her temptation and it far enough away that she'd really have to work at it to get her hand down the disposal and flip the switch at the same time. I agree the switch is beautiful. At the island prep sink I added a switch under the counter for the disposal. The kids think that is pretty cool and showed it off to friends when the kitchen was first done, but now, out of sight out of mind. They don't touch it. I love my soap dispenser (the NeverMT is a must!) and use it a lot. I still have a bottle of dish soap on the counter and use it a lot too. It just depends on what I'm doing but I love having both. I tend to grab the bottle of soap (I keep it in a pretty olive oil dispenser) when I want soap in a specific place, like a pot or pan that I'm washing. I tend to use the built in dispenser when my hands are dirty or I want to pump some soap on my sponge. There are a lot of pretty dispensers out there if you want to keep soap on the counter. We don't use a separate hand soap and only use dish soap in the kitchen. I used to have a lotion dispenser in my previous kitchen and got so tired of people trying to wash dishes or their hands with lotion. I found people pumped first and asked questions later. And several times well meaning people added soap to my lotion dispenser. UGH!!! At least a NeverMT would stop that problem. But I found the lotion dispenser drove me nuts more than it helped. I'm just going to put out a pretty lotion dispenser in this kitchen. As far as mixing the Waterstone air switch and filtration faucet with another brand of kitchen faucet, it is just going to depend on what you pair it with. As long as they look good together, should be fine. It's totally going to depend on what finish you use and the quality of the other faucet, so hard to say.