some sites don't work (you can explicitly whitelist them tho) but generally it's been fine. i would honestly prefer a phone that doesn't allow any comms to any non-contact list parties at this point.
From what I can see in Apple docs, aside from web limitations it sounds great. Is there any real reason to not enable this? Like I would be deeply suspicious of a PDF sent via messages and no auto-connect to insecure WiFi is also common sense.