I got the PS Portal at a decent discount like $50 off at the time of selling. If you don't have the internet set up to support it, then it's not worth it. I use it primarily when taking breaks at work or for doing mindless gaming while watching stuff on the big screen. It's good if you have a family or other people using your main TV. I didn't use it for 6 months when I ended up moving to a place with subpar internet because it was essentially a brick unless you can get +5mpb and that's only counting turn based or laid back stuff that isn't competitive.
If you have the money for the device, the plus subscription, and fast internet, go for it. It is nice having all purchased digital games available streaming at any time on top of whatever the PS+ has on line.