As for the PROC vs other board sets, honestly they should just pick what works best for them. If Ben is coding it, there is no doubt it will be his board set that will be the quickest solution for him.
We went down the path of PROC vs something else, and we picked something else first. While the cost savings to the BOM looked great for us when looking at the retail pricing and low quantities, that pretty much evaporates at higher quantities.
I can say that the boardset costs for Kingpin are quite a bit lower than we expected when looking at quantity pricing (believe me, looking at retail pricing scares the shit out you at first), and that coupled with the documentation, multiple frameworks/tools available, and support from their dev community all saved us a**loads of time.
For us, PROC was the right choice, but I fully understand that for others it may not be.