They're good... but...
We sell them. I've sold a couple.
They're really nice bits of kit, no mistake. They also make sense if you're in the ecosystem.
However, I would suggest the use case is fairly narrow - if you're doing truly collaborative whiteboarding across different sites, and you need an excellent hand drawing capability, then they're bang on the money. Software planning, marketing/advertising, engineering, etc etc.
If your use case is to just webex/teleconf, and batter the snot out of people with slideware, then just get a Cisco Spark board because it's a damn sight cheaper.