Are we able to control these with ST? I would love to get nice dimmers like this if they had all the features of a standard Z-Wave Plus switch 
You need the Lutron bridge , which comes in the starter kit. Caseta are proprietary 433Mhz, not ZigBee or Z-wave. So they will NOT help your mesh. It is a C2C not LAN connection between ST and Lutron, but yes they do work.
Thank you for the info! Sounds like not a great solution. I’ll stick with my original Z-wave devices
But they still respond faster than my GE dimmer switch. I love my Casetas. And the Pico remotes are great.
Excellent price! 
Just one note: if you get the standard smartbridge, which is the one this package has, The official smartthings/Lutron integration will work fine for the master switches and the picos will work well as a virtual three-way to control the master switches. But you wouldn’t be able to use the picos for any other smartthings functionality, as the picos themselves are invisible to smartthings in that configuration.
If you want to be able to use the pico buttons for other things, like changing modes or arming smart home monitor or even to trigger a smartthings Scene, then you need to use the unofficial integration and you need to get the “smartbridge pro“ model. (Same thing if you want to use the devices with hubitat. The pro model offers additional integration options for third parties which will expose the pico button presses.)
For most people who are just looking for a three-way switch setup, the standard smartbridge is fine, but I just wanted to mention this so nobody has to say “oh, I wish I knew that before“ as far as the pico integration.
Much like how ST doesn’t see any of the Hue accessories like dimmers, taps, motion sensors attached to the hue bridge. It only sees the lights.
Just for the record, the Casetas are faster than anything I have connected to ST and they work great ZERO issues other than a few flaky bulb issues …
While lutron does make good equipment, the Z-wave plus switches/dimmers are instant from my experience and I do not need another hub, plus they can work locally.
I’m glad they’re working well for you, and there are many reasons why someone might use Zwave over Lutron, but Lutron devices are spec’d at 500 ms or less, while most Zwave devices are spec’d at two seconds or less. Many people won’t care, but there is typically a measurable difference.
You are still dealing with cloud integration and 2 separate hubs which all create additional latency, if you were just working within the lutron hub system, then yes it is fast. I was also never crazy about the pico remotes because of the need for batteries, instead of mains powered.
Lutron makes good products, I just really do not like to be tied down to a closed system, at least with Z-wave/Zigbee I can use any hub I want for the most part.
The battery powered hangup is a funny one considering almost all the sensors for smartthings are battery based. Also, the pro hub has local telnet control so no cloud latency with a local controller either.
You forgot to mention that the caseta will now work with thermostats and mini blinds, nut not with Samsung TV. Oh, wait…
Lutron Caseta is a fantastic solution for switch boxes without neutral wires.