So it is mounting after all. I say forget about the crap pushpins and pay $30 for a real heatsink with backplate.
Push pins work perfect. You have to know how to put them on. When done properly they work just like they are supposed to. When you got a pin in the open slot you can hit it with a hammer and it wont lock in.
The other flaw is from people when the mount the mobo in the case and the try to push the oins in and the mobo flexes and the pin botoms out on the mobo tray not allowing it to go in.
If you pins are all in the lock position and you lock em in the mobo out of the case its so easy a baby could do it.