I remember hearing a tip from cleaning expert Shannon Lush warning about the vacuum storage bags. Something about the plastics used and the interactions with the clothes can make them go yellow. She recommended if you use them, put the clothes in an old pillowcase first so that you protect them.

I just googled [shannon lush "vacuum storage bags"] and it came up with a google book review link for her book "household wisdom" which talked about this and advised to make sure clothes are properly washed before you store them as any tiny amount of bacteria on the clothes will thrive in the plastic bag and leave yellow stains.

I think if you take these precautions, the vac bags are a great way to keep the clothes and gear you love and may want to use again. I have heaps of clothes in storage at the moment, waiting for a friend's baby to be born