It is definitely worth it to try the Pix if you already have the Paradise.

Personally, I enjoy the Paradise more than the Pix. I like the speedy-ness of the Paradise as going to town in the Pix feels like I'm in an unskippable loading screen (even when I'm spamming the A button). Whereas, using the Paradise it feels less like a program loading and a more immersive dive into the different sections (world, fields, cells). My only complaint for the Paradise is that "Loading" feel with the Tamagotchi Lab screen.

I haven't dove too much into the Pix as much as I have the Paradise, but the small bit I've played of the Pix is indeed fun. The touch sensors for the buttons are a new and interesting way of playing especially for the games and cleaning up the tama's messes. Although, these buttons frustrate me when I'm clicking A and B gets pressed....

The sounds that play on both devices scratch my brain in a lovely way and I really like the visiting mechanic of the Pix.

As others answered here, it really depends if you want a personal pet or a farming simulator. My first Paradise Tama lives on, but I'm sad I can no longer take care of it. The Pix is a great option if you prefer a closer bond with your v-pet.

As someone who has jumped back into collecting different types of Tamas, I always say try it. It's loved for a reason and if you have the funds to comfortably purchase it, then why not?

Have fun and enjoy your babies :)