I had an x-33, so not technically who this was addressed to.
I like the x-33 for its ascetics, fit on the wrist, and gadgets. I enjoy pushing buttons, so it was fun cycling through features. The countdown was fun, as was checking the time in a different timezone. I never used the PET, although i could see how it could be handy.
I no longer have it because of my desire to reduce. But it's a fun watch.
The Skywalker is the prettiest, in my mind. The orange on the Marstimer is a nice look too. What would keep me from getting a Marstimer is the connection to Mars. I don't need to know the time on Mars. I have a photo of the sunset on Mars. So I am excited by the idea of exploring Mars, just not by humans going to Mars. I think that's a big appeal of this watch and one that a person would need to be behind in support.
Good luck with the decision.