the floor press is different for different people. i had a friend that could do a 405 but couldnt bench 405.
personally, if i use a close grip, no equipment, and i fully stop my elbows on the floor before reversing the motion, i am 100 - 150 lbs under my contest bench.
this is why i LOVE doing these. I have found an area I am weak at. you should strive to find these spots.
If you can bench 500 and you can 5 board press 500, it is not really necessary to work your 5 board press as you are strong enough in this position. however, if you are only floor pressing 350, this area could definitely use improvement.
this is my opinion. i used to love working lifts i was really strong at, but if they dont carry over to contests, what is the point?
/irish