I think the 4 Board Press is one of the best lockout exercises you can do. Also, I've used it as a ME exercise and for whatever reason, when this went up, so did my max bench press.
The 4 Board Press is generally used as a supplemental lockout exercise and is especially useful when doing multiple sets of 3-5 reps. This is generally done as a second exercise (after ME work, DE work or rep work).
When doing this, any grip can be used (close, medium or wide) but I have found great success when using a medium grip. This is classified as having your pinky finger on the ring.
Make sure to bring the bar into the boards, let it sink slightly and press. Do not let the bar sink so much that you use the momentum to heave the bar up. This is cheating and Congress will call you to testify in front of a Grand Jury.
If you are having trouble locking out big weight, this is a great exercise to do. If you are holding the boards, you do not have to look at the camera.