This is entirely a choice based on how you set up your house for lighting control. I bought a home that had the original "classic" RadioRA already installed. In some areas, there are no light switches, only keypads. I have since replaced that old system with RadioRA2, and kept keypads in the same places for the same functions. Having said that, we don't use these keypads as primary lighting control. Instead we use Hubitat apps and Alexa. But, when we do use them, they have augmented functionality only possible with Hubitat (e.g., having the lights dim based on mode, so each button becomes mode-sensitive).
seeTouch keypads are what I would call "designer" keypads. One reason that people choose RadioRA2 is because you can get switches, keypads and wall plates in numerous "designer" colors. These choices are not available with Pico keypads. In addition, you can have multiple lighting scenes on one keypad, with raise/lower buttons that apply to each of them.
If you go with RA2 Select your choice for keypad is limited to Picos. I love Pico remotes, they are great. But they are not what you would call "designer". When wall mounted, they look just like a Caséta dimmer, and Lutron intended them to be used that way. With Hubitat, you can free them from that constraint, and use them however you see fit. So it is very possible to use a Pico as a 4 or 5 button keypad. It is also possible to get raise/lower functionality from them even when not paired with a Lutron dimmer.
The other major difference between RadioRA2 and RA2 select is how you program it. With RadioRA2 you must use the Essentials (or Inclusive) software that runs on a PC to setup and program your Lutron system. With RA2 Select, you use a mobile app -- the same app used for Caséta. Essentials (or Inclusive) offer more choices for detailed setup of a system that is made up of a variety of Lutron dimmers, switches, etc. This software is intended for professional installers. To get the Essentials software you must complete an online course that Lutron offers for free. To upgrade to the Inclusive software you must complete an in-person training session (RA2 Level 2) that costs $400. The Inclusive software is necessary to use two Main Repeaters, and has a few other features not available in Essentials.
seeTouch keypads are expensive, come in multiple designer colors, come with free engraving for the buttons, look very nice, have LEDs for each button, and work very well. This is a high-end keypad, mains powered, and wall mounted. Picos are cheap, come in only a few colors, can be engraved (not cheap), and have a single LED, and work very well. Picos can be used as a loose device, mounted on a small pedestal for table top, or wall mounted; have 10 year battery life.
