Jim,
I call the Fatboy my Tactical Man Purse.
Then my wife rolls her eyes and says "bag"
The bag can get heavy, but it is all relative.
A pile of CD's in a round zip holder, bottle of water and my E-Kit makes me notice it's there.
The E-Kit has garbage bag, ltwt rainponcho, dustmask, leather work gloves, 2 bandanas, Black Diamond headlamp, Gerber sharpsteel (prybar in disguise), Swisstool Spirit, GI bootlaces and notebook and pens.
And then there is the day to day crap. 2 pairs of specs...
Without the CD's or book it aint bad.
I guess it is too small to really jam alot in there.
I will say that it is quite comfey.
If I find a scale I could weigh it

I don't think you'd be disappointed.