+1 to enharu
Depends on where you stay most often. Should be a pretty straightforward thing. No point in changing what hotels you frequent just because their card is better. IF you stay at one all the time, pick that card. 
Hopefully this isn't just an "I want a metal card" thing
@jsucool76 wrote:+1 to enharu
Depends on where you stay most often. Should be a pretty straightforward thing. No point in changing what hotels you frequent just because their card is better. IF you stay at one all the time, pick that card.
Hopefully this isn't just an "I want a metal card" thing
+2. Your choice of CC should be determined by what hotel chain you frequent most, not the other way around. As for general guidelines:
If you frequent Marriott hotels already, then it's a decent card to help with that. Also Marriott has a lot wider coverage, so unlike Hyatt you'll find more properties outside major cities/resort areas.
However if you're a light traveller, have a decent-sized travel budget (since Hyatts aren't cheap, especially their international properties), and there are Hyatts where you want to go, it's a good choice.
The Hyatt card comes with platinum status which at least gets you free internet. Marriott only offers silver with their card, so you'll still be ponying up $10-20 per day for internet when you stay at their properties.