Is it an upgrade?

I'm still trying to learn about what's what with my old FS bike.

There is no adjustability on the fox vanilla, and it is a bit bobby if I don't stay seated and crank as smooth as possible on the uphills.

the fox vanilla is I think from 1999.

I'm assuming it's an upgrade to use the manitou swinger air 4 way from 2005?

This is for a 1999 DBR x2

Thanks for your input.