Like others, I find this promotion to be weak compared to past SPG offerings. It doesn't make it a bad promo, but based on the participating properties it certainly limits the earning potential for some.
It's a nice bonus to have for my existing travel plans where relevant, but I can't see it driving me to make too many additional stays. That said, the counting of multiple rooms is a nice touch and that alone should push me to the 10 night and triple point bonus during the period.
From looking elsewhere though, I'm not sure the rest of this year is looking too great for promotions overall compared to the first half of the year at any of the major hotel chains. In that context, this probably is par for the course.