The front rail is good for sitting while climbing too. I have an API with an open front, and have to stiff arm the climb. No big deal for me, except it may make you sweat compared with one with a bar. Also, if you are old or injured, you might have problems scaling a tree with an open front.

One thing to keep in mind when bowhunting, keep the seat as close as you can tothe platform while remaining comfortable. That way when you stand to shoot, you are less likely to knock the bow against the seat portion of the climber.