Best in-wall light switches?

Just this week, there was an announcement at CES 2017 that there will be an official integration between SmartThings and Lutron Caseta, with Lutron staff saying that they are expecting it before the end of February. So you might want to wait to see if that happens, those are excellent switches.

For consideration of other options, the following thread should be helpful. The discussion of switch features starts around post 40.

As far as zigbee versus Z wave, zigbee can get drowned out by very strong Wi-Fi, so it’s usually the less desirable choice for fixed location devices like light switches. That is, the more you do to strengthen Wi-Fi throughout your home, the more likely it is that you might interfere with some zigbee operation. With sensors you can usually work around this, often just by moving the device a foot or two in one direction, but since that’s not an option with light switches, zigbee light switches are usually less popular for DIY projects. (Professional installers have tools that can help them get around this issue.) there are of course many people using zigbee switches successfully, it’s just something to be aware of if you do have the choice to use other protocols.