Not who you’re responding to, but I use both. For calls, Tesla’s isn’t bad, but I prefer CarPlay because my favorites are front and center and the car’s voice recognition doesn’t work well for me. (Don’t help my wife name is an uncommon, but similar sounding to a common name. It’s always a 50/50 shot if I call my wife or a coworker when I ask the car).
For messages, I get a lot. I have the car read them to me. If it’s a message from a single person, Tesla’s system works great (although again, voice recognition isn’t great for me). But it completely falls on its face with group messages. Maybe I’m doing something wrong, but it never tells me if it’s a group message or not (just “Person A wrote”, did they send that to me directly or in a group message? Tesla has no idea) and there is literally no way to respond to a group message though the car without picking up the phone, which is obviously not safe.
Don’t get me wrong; Tesla’s system is absolutely better than any other car manufacturer. It’s legitimately great. But calling and messaging is, in my opinion, definitely better in CarPlay. So I’ll handle calls and texts (and third party apps) via CarPlay and everything else via Tesla. Best of both worlds!