If you are a PS5 user, the Portal is going to feel very familiar. It is basically a DualSense controller split in half with a screen in the middle, so right away it feels comfortable and natural to hold.
The first thing to understand is what this device actually is. The PS Portal is not a standalone handheld console. You cannot install or run games directly on it. Instead, it connects to your PS5 and streams your games over Wi-Fi. That is the whole point of it. So if your Wi-Fi setup is solid, this thing works seamlessly.

The screen is not OLED like the Steam Deck OLED, but it is still a really good display for a handheld. Pair that with the DualSense triggers and haptics built in, and it feels great to play on. For story-based single-player games, especially, the experience is excellent.
For me personally, I do not do a lot of gaming. If I am at home, I would rather sit down in front of the big screen and play on the PS5. If I am out, I prefer using the Steam Deck. But I can see exactly where the Portal fits.
Imagine your PS5 is set up in the family room and someone else wants to watch Netflix. With the Portal, they can watch, and you can keep playing from another room. That is where this device makes the most sense.
So yes, the PS Portal works really well for what it is. If you already own a PS5 and understand that this is not a full handheld, then this is a great addition. For some, it might feel like an unnecessary extra since it cannot do anything without the PS5, but I think Sony knows this is for a specific type of player, and that is fine.
What excites me most is what it hints at for the future. Using the Portal made me realise how capable Sony is at building a handheld device. It really got me thinking about what a new PSP could look like, and that is something I would love to see.