TLDR after watching and reading these:

It’s a good remote play device and little more. You get better ergonomics than other methods, full dual sense haptics, and the screen is nice. You should use remote play with a device you already have and depending on how it runs on your personal network and circumstances, that is what you should expect from the Portal. In the Tested Review his iPhone was able to perform a single frame faster than both the Portal and the SteamDeck running Chiaki, although he said this was not noticeable in gameplay, only under analysis. Audio options are limited to 3.5mm wired or using a PS Link compatible headset. No review has tested USBC audio out for potential use with a USBC dongled wireless headset (like my Arctis 7). SpawnPoiint tested the USBC port for Ethernet and wireless USBC dongles and neither work. And if you are playing at home, I have personally tested (using my phone and Arctis 7) that you can leave a USBC dongle in your PlayStation 5, establish a remote play connection, go to the audio out settings and force audio out through the USBC. The digital trends article did try to do USBC video out and connection to a dual sense, both of which did not work (why they didn’t think to test a headset dongle is beyond me). In the SpawnPoiint review he was able to show a 82ms delay between his TV and the Portal using a timer from a racing game displayed on each. Lastly, no reviewers seem to actually have the Pulse Elite or the Pulse Explores in hand to test with this. I expect the headset reviews to come later.

Personally, I will be keeping my pre-order as this experience is exactly what I expected. I already remote play on my Steam deck using Chiaki, and my main pain points are the lack of haptics, the smaller 7 inch, 720p screen (technically 800p but I don’t stretch the aspect ratio), and the less vibrant display. I’m looking forward to getting this myself to test it out, and it should come Wednesday, so if anyone here has specific questions not covered in these reviews, let me know and I can test for you.

Edit: added from the IGN review: While the reviewer had a great experience streaming from a local coffee shop with a PS5 back home on WiFi (not wired), they did note that the Portal has no way (currently) to deal with the typical login screens that you get on public Wi-Fi. I think this is a big deal if you plan to use this in any hotel, airport, or really anywhere that requires you to accept a TOS for you to access the internet. Of all the negatives about the Portal, this is probably the biggest one as of yet (other than Bluetooth). Hopefully Sony fixes it in a software update, but no one should be buying this device hoping that it’s better in the future. You should only be buying this device if it’s current feature set, fits your wants and needs.