Disclaimer: The following is based off my experiences, YMMV.
I’ve had the Marriott Premier Visa
for a few years now and have not had a problem achieving Gold status. They give you 15 nights and you need 25. Gold is the first status level worth anything with Marriott. You could save $50+ a day with the free breakfast and Internet. The free night each year is a nice bonus too.
I also really like the $3k in spending equals 1 night credit towards elite status. That way if I am a few nights short for the year I can just shift my spending to the card and make sure I get Gold by the end of the year.
Marriott has really stepped up their phone based customer service. In my experiences every time I called with an issue they resolved to my satisfaction—even after web and email initiated requests had failed. Chase has also placed an emphasis on their customer service lately. You can now reach a live rep immediately; as a contrast, with my Amex Platinum I have to go through several layers of automated prompts to reach a live rep…
Properties are nice and consistent but I have never been wowed by one. Points were recently devalued which makes it harder to get anything out of them but if you save them for the right time you can usually find an undervalued gem and make a good score.
My Marriott Gold is secured through 2014 so I have a chance to explore SPG. I have been reading a lot of good things about the SPG Amex and program in general so I just picked up the card. I have no experience with the properties or card though so I’ll leave that to someone else to discuss.