And I highly recommend everyone to follow your advice. Don't stay at a hotel for the sake of miles and points only if you singificantly prefer another property with lesser or no points/miles a lot more. You are probably referring to my spreadsheet in the SPG forum, it wasn't intented as bashing the value of SPG as a program. On the contrary, I really like SPG, both the program features and its hotels. Without SPG, I wouldn't have a default FF currency to trade with people on FT with a sensibly stable benchmark. Also, numbers usually fail to translate the non-quantifiable factors such as usage and the pleasure/satisfaction gained from those. Just because you can't see it doesn't mean they don't have value!

To the OP, the good thing about SPG is you can transfer your points to miles when the need arises. Put it simply, there is not a single best FFP to pair with SPG because each FFP has their strengths and weaknesses. Someone mentioned CX Asia Miles as a good redemption opportunity for Business class tickets to Europe but if you want to fly BA F on the same trip, it would be best to use Japan Airlines MLB, which is cheaper than both CX and BA for instance requiring only 100K miles. So it really depends on what your needs are and where you want to go. If you transfer all your points to AA and yet suddenly, you want to take your family on a summer trip to the world famous Anne's Green Gable in the beautiful Prince Edward Island on Canada's Atlantic coast, you are out of luck.

Hence, the best strategy re: SPG and Airline FFP IMO is to save your points as SPG point and transfer them to miles once you decide where you want to go and which FFP best serves your need.