Incline Angle - 15 or 30?

So I'm "patiently" waiting for Rep to get the AB-4100 bench back in stock (and maybe score a November deal??). My current cheapy bench is ok but I feel like treating myself and can really use the upright storage of the 4100. I see that typical benches (including mine) start at 30 degrees for incline which is fine but I noticed the 4100 starts at 15 degrees. I'm sure they consensus will be "try it and see what works better for you" but just wanted to see what the hive says.