I got the easy-fill hydration bladder adapter for mine. It let's you fill your bladder using the bag that came with the mini without taking it out of your bag. It is extremely convenient. You can also pop the quick release off and create a nice spout for cooking, cleaning, etc. you just lift the opening above the bladder and pop the quick release back on to shut it off. I haven't put them on a scale but I can't imagine the components weigh more than .2 ounces.
http://www.rei.com/product/858765/sawyer-fast-fill-hydration-pack-adapter-kit
You just need the the 2 little pieces with the mini, not the threaded cap.
I read a lot of complaints about the fill bags which came with the original squeeze but it sounds like they updated them for the mini. I like the bag it came with. the only complaint I have is that they don't fill very well by submersion – you are much better off finding some falling water.