Truth is I dove the SP Jets for years and HATED the foot pocket. My toes were the only thing that fit inside them and as I only used for tech if I took a break from tech and had been doing lots of rec dives it would take a couple days of pain when I went back to the jets before they were ok again. The foot pockets on my Deep 6 Eddy fins have NOTHING in common with SP jet pockets. The sizes don't correlate, the shape is different and the way they fit a foot is actually designed to support the foot past the arch and not lose a whole bunch of energy by side to side movement and only having the toes and small part of the foot ahead of the arch in the pocket.
If my XL is too big, the large will probably fit. In my experience I have no idea at all how or why Scubapro called their large Jetfin a Large, it's a smallish medium at best IMHO, their XL is sorta a large (for the width but not really anywhere else) but not a XL compared to the majority of fins on the market (except the jet copies that also copied the pocket.. uggh) and their XXL makes me wonder what they were thinking because they introduced it fairly recently and could have done so much better but look like they just scaled up the existing foot pockets with no consideration for the shape of a human foot or how the existing Lg and XL actually fit in real life..but hey, it's their product and it is a awesome selling one so who am I to say?
I have posted picture comparisons of the SP large and mine, and the SP XL and mine.
You can find a whole series of pics of the SP and mine side by side at
DEEP SIX - Photos | Facebook