You'll have to judge for yourself whether or not the sound is right for you, but as other people have said this is currently *the* FM synth in Reason, and if you want to learn how to make patches for it (it's not as easy as Antidote or even Thor) or if you can find existing patches that you like, then it's a great addition to your rack.
If you're really not sure what you like yet though, and you want to explore a lot of different sounds, you might also check out some Refills in addition to Rack Extensions. Stuff like Fairlight Platinum
(or even one of the smaller and cheaper versions you can find on the same site) for example. It's based on the Fairlight synths, but there's a wide variety of patches there, and there are also samples from a bunch of other instruments, including the DX7 (which the PX7 is based on).
If you like the sounds you hear from either the DX7 or PX7 then give it a try for yourself.