I omitted this from my Cabin Skiff. If I remember correctly it would have allowed about a 12" step down. As is, I crawl in and out. As per plans it is a fairly small opening and would require you to step in, turn 180 degrees and then try to sit down while facing aft on a deck that is only 12 higher than the bottom of you feet. Not sure it it would make it much easier plus it just looked to me like a great way to beat the back of my head on the berth top beam. Also, the berth is small and I could easily see junk constantly getting knocked into the well and ratting around.
Here is a photo of the area it would be built. It would be just forward of the athwartship beam.
BUT, I certainly could be wrong. Any one else out there that did include this?