The real question isn't really the "point values" as the earning and burning of points is different with each program. Just saying that an SPG point is worth more than a Marriott point doesn't give a complete picture.

What you really need to look at is what your earning potential would be for each program versus what you would use those points for. Also, where will you be traveling to? Does Starwood and/or Marriott have hotels that you can stay at? And also, depending on your stay patterns and volume, you could easily move up the elite food chain. As such, do elite benefits count for anything? Free breakfast? Suite upgrades? Service? Hotel consistency? Hotel variety? Lifetime status? and so on.

What is important to you will ultimately help you decide which program will work best for you. You have links to discussion threads from your query in both forums. Take some time, read through those threads, and I might even suggest look around both forums and you will find other threads as well. They can be very enlightening, but in the end, your unique situation and desires will dictate which program better fits your needs and desires.