I love my Murmur - the straps themselves are wide - probably about 2.5". I found the foam inserts included to be uncomfortable and replaced them with bubblewrap rolled up in each strap - very comfortable.
I'm a big guy (around 260) with broad shoulders and probably look somewhat ridiculous carrying such a small pack, but it's easy to carry and holds everything I need for a weekend quite well. You can see it in my avatar.
I keep my 2 liter Platy hoser in a side pocket and my tarp and raingear in the back mesh pocket. I did add the GG Large Hipbelt pockets (GG modified them for me to fit the 1/2" hipbelt on the Murmur. That's where I keep my camera, some snacks, first aid kit, and other essentials.
Oh yeah - I use the GG Nightlight Torso pad in the pad holder...