I own points at Poly and Riv and love both resorts (also own BLT points). I will say, if you want convenience for RunDisney weekends, poly cannot be beat. I have done 2 and the ability to walk to the starting line at the TTC cannot be beat. The last one we did, we were with others who stayed elsewhere, and they had a whole different experience that morning (e.g., getting up much earlier, in a morning that starts really early, to catch a bus, etc.). I have stayed at the poly over a dozen times throughout various times of the year and have never had problems getting a studio.
Riviera is also a great resort and we find the Skyliner to be a really easy/quick way to pop in and out of parks throughout the day.
I have a mix of direct and resale points and have no regrets with either. They key is knowing what you want the points for and if the direct perks are not important, then go for resale. Lastly, this should be considered a long-term commitment, and if you are not absolutely committed to holding long-term, you may want to think twice. So, if the resale restrictions on Riviera are holding you back, then that may be telling you something.