I had 2x120mm strapped into my Myst on the original heatsink. Now i bought a Accelero S1 Plus. I can say it fits perfectly, also in my case.
2x120mm fan mod:
load: 79c core, 90c VRM on 1150mhz / 1.1v
S1 Plus with 1x 120mm strapped on:
load: 65c core. 70c VRM on 1150mhz /1.1v
S1 has a significant better airflow as my VRM temps dropped hugely. Didn't even remove the vrm heatsink or replaced the pad.
These numbers are after 2h of folding in Unigine Heaven. I wasn't able to get more on the core but i have now 1600 stable on memory. (i used memory heatsinks that came with the cooler)
All in all i don't regret paying 15€ for that cooler. I got some good temps now (also on VRM) and its even quieter now + looks way better
And still 50€ below the price of a 7950.