i'm not a red thumber either.
you could always just look at the board and get a rough understanding of how it will work.

I think sue you need to be careful that you don't keep asking the same questions or rephrasing the same question until you get the answers your looking for.
the only way to really know how a board performs is to sail it as sean has said.
anyways, it's just an opinion but I think that the scross would be a good substitute for your 125lt board. it's hard to shop for boards just based on max width and volume which is what most intermediates do. there are better ways, like looking at the volume distribution, the one foot off dimension, the length, the rail shape, the rocker, the nose rocker, the bottom shape, the thickness of the board, the materials used to build it. all of those things have a greater effect on early planing and how the board reacts to chop.
just as an exercise compare visually the scross versus the rrd freestyle wave of the similar volume and width. do they look the same?