While I dont own one of the packs you listed, I can say that I have tried them on and worn them for extended times. (I wear them around the store while working to check them out... yea, weird, I know) They are really just down-sized versions of the larger Z-series (50,55,60, 65) and have the same features with the lumbar and shoulder padding. I find them quite comfortable. (And they are on sale!!

)
For a daypack, Id suggest the Z22.