The Palm is a beautiful little thing, crafted from aluminum and Gorilla Glass 3, but I couldn't imagine using this thing all day. To be clear, you're really not supposed to. For one, its octa-core Snapdragon 435 chipset with 3GB of RAM is probably a fair bit slower than whatever's powering your main phone, so the sort of multitasking you might be used to could be a little difficult here.
It isn't meant to have its own phone number, either. For now, at least, the Palm is a Verizon-exclusive, and it uses the carrier's NumberShare service to sync your messages and notifications between your main phone and this thing. That's great if you want to go for a bike or run a quick errand without your phablet. It's decidedly less great that iMessages you received on a NumberShare-enabled iPhone won't get routed to the Palm. That might sound pretty "duh," but Palm is pitching this tiny Android gewgaw to iPhone users too, so keep that in mind.
And beyond that, there's the whole battery thing to deal with: there's a sealed 800mAh battery tucked away inside, which Palm claims will last about 8 hours on a single charge. You can extend that battery life a bit with a feature Palm calls Life Mode, which — as the name sort of suggests — is meant to help you disconnect when needed and focus on what's happening in front of you.