Quote Originally Posted by novastepp View Post

I totally agree and I want to add that for me, I keep shoulder blades pinned in and down the entire time but I do not cave my chest.

Also, I find it much better on the ROM to over arch my back at the bottom/stretch of the movement. I do not over arch my back during the pressing/contraction of the movement. The arch helps with the stretch and ROM, but does not benefit the flex at all.
^^^^^^^This !!!!!!! Keeping the shoulders back and down when doing DB or BB bench protects the shoulder joint plus adds stability. This is how most PLs bench. There's no need in letting the DBs touch at the top. If they hit too hard it can throw off your groove and it doesn't accomplish anything by letting them touch anyway.