It really depends on what you are looking for to be honest. The Pix is currently one of my favorite modern tamas, and it is by far my favorite of the color tamas, although my experience with color tamas is not very broad as I have a softer spot for the older tamas and as of lately some of the nanos. Unlike with the On, you do not get to mix genes or marry your tama off, although you do move on in generations. Once your tama reaches a certain age, it will leave back for tama planet and send you back an egg, marking the start of the next generation. That said, unlike the On, there is a definite want to bond with your tama on the Pix, as bonding with it will actually allow you to keep your tama around for longer, having it give you the option to not send it away as soon as it reaches the right age and instead keep it until you choose it's time to say good bye.
There are currently six different shell colors for the Pix, and two different versions. The regular Pix comes in pink, purple, blue, and green. The Pix Party, which would be the second version, comes in Confetti - pink and teal - and Balloons - purple and magenta - colors. The two versions are fairly similar, although there is a minute difference in rosters per version as well as some games replaced for a party theme on the Pix Party. As for what you can do with it, it's pretty much a modern tama in that regard. You play with it, you feed it, you bathe it, you take it out shopping, you play games, grow fruit in your garden, pet it, cook with it, build and paint furniture, train them to get a job once they reach adulthood, etc etc.
There are cons to it as well. The battery life is abysmal in the pink and purple versions. I have heard that the blue and green have better battery life, along with the Confetti and Balloons version. There is currently a confetti in my house, but my husband is banning me from opening it until my birthday proper, so I cannot confirm if this is true.
There is also the fact that some users find the touch buttons on it persnickety. I have never had problems with my pink Pix, so I cannot say if this is a case of the devices being faulty or just some people having a harder time with the buttons than others.
Overall, to me the Pix is well worth it. That said, from what I have seen, it mostly seems to be a love it or hate it tamagotchi. Others might better help there. That said, I think only you can tell if it's worth it for you or not. It is much pricier than the P1 and P2 rereleases, but much cheaper than getting just about any other color tama at the moment. If the idea of raising more classic tamas with a more modern device and gameplay is something that appeals to you and you have the money, I don't see a reason not to get one, but I am biased.