Let's Say A Guy Wanted To Chose Between A Koetsu Jade and

Blue Lace is the most dynamic Koetsu but still sweet as hell, Jade is warmer - warm even for a Koetsu. My preference has been Blue Lace from hour #1 but both are undeniably Koetsu sound.

Difference between platinum and non-platinum is probably the most important factor. There is a diversity of opinions on that.

All Jades and Blue Laces have Platinum magnets, as far as I know. Onyx is the older model that has some non-Platinum magnet versions floating out there. I have an Onyx with Platinum (early P - #P022!), and one without (Musashino Labs), both rebuilt to 2018 Koetsu spec. Yes, the difference is quite significant. There is a reason they moved to Platinum magnets (from samarium cobalt?) for their modern motors in stone bodies lol. It has more of the creamy, sweet sound you'd expect from Koetsu thanks to the platinum magnet, but better clarity, bass and dynamics from the stone body and new motor spec. 

I'll keep in mind that platinum magnets make for a creamy sound.