TBH Molgrips has it, demo the frames you like, and decide based on that.
I really like Giant’s Maestro frames for their stability, Specializeds Horst link for it’s ‘dead’ feeling (it just did it’s job without flaws, I did mine and the bike went very fast), single pivots for their ‘lively’ feeling (lean back it squats, lean forward it extends, bad if you’re writing marketing spiel, good if you want to feel involved in the riding).
I’ve never ridden a VPP I liked, but maybe that’s just me.
In terms of acronyms and small-fiddly-parts count there’s nothing between VPP and FSR, but they make different bikes, and there’s plenty of different ways to arrange a FSR frame as well (Nicolai put the top link upside down, making it more like a VPP, but still doesn’t feel like one).