My cheap Gelert duffle is starting to show it's age, with a few small fabric tears at the seams. Which got me thinking about making a new duffle, but nicking the carry straps off the Gelert.
I looked at the design and wondered why it's barrel-shaped... The only reason I could think of is to eliminate the need for sharp corner seams, which are vulnerable stress points. I'm sure a gently-rounded rectangular corner would work just as well.
Fancy axe points are all well and good, but not everyone needs them. So they're limiting the versatility of the bag (or adding dead weight when not needed). I use axe head & spur protectors made from lumps of recycled EPE foam packaging.