No idea on weight but the MG buckets are incredibly light bags anyway I can't see it would make too much difference.
I have had them in mini mini, mini and regular. The mini was by far the best size wise. It held my essentials with a little room to spare. The mini mini held the bare minimum and I had to leave out my pouch and hard sunnies case so therefore had to rearrange the stuff I need to carry just to use it. I found it very impractical so it depends what you carry.
Thank you. I carry just the minimum daily and maybe both sizes could work. The mini seems like a good size