Double crown or single crown with qr20 ?

Hello, I have a choice beetwen M Jr.T ( fixed to 150mm travel ) or a single crown fork but with
qr20 axle ex. Z1 FR 2002/2003 or maybe Shiver SC. I consider what will be the best choice for me, i
like agressive xc , fr and sometimes easy dh. Z1 MCR is to flexy for me and i want to replace it
with stiffer model. Maybe someone had a chance to compare double and single forks with familiar
travel but but with different axles ? And one more question what is subiectively difference beetwen
Z1 FR 2002 and 2003. I know tech info about it but i dont know anyone who has 2003 model, so i
havent try it.

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Pozdrawiam, TK R 214Si Giant AC Team