I have the Wimberley WH-200 and I am looking to add the M-3.5b as a backup for light weight travel deployment. Anyone have experience for both and would you recommend getting a M-3.5b?

I have the wimberley wh-100 and mongoose 3.5. I love mongoose for when I am doing a fair amount of hiking. I find it a good lightweight alternative especially with the replacement foot for the 500mm that they have. I use both and think both have their place in my equipment line up.