the new NAN02 is a different extraction method and is stronger. it is personal preference on what you use.
v02 and NaN02 hit within 30mins and last upwards of 3 hours. this is more suitable for gym goers and crossfit crowds etc
c5 is a delayed release (DR) which takes about 45mins to 2 hours to be fully absorbed, but, c5 lasts for 8 to 10 hours. suitable for endurance sports.
I have used every single MST product and my favourite is v02 with cre-02 a close second.
if you have any questions, pm me. I'm not an MST rep but I have a soft spot for MST and are one of my fav companies.