The convenience of not having to lug a pram around in a car, on trains, through crowds, in and out of aisles outweighs any concerns I have about being a 'packhorse' LOL!
My GR8 Expectations nappy bag is ace and I still use it - I slip my wallet and valuables into the back pocket because this rests between the bag and my back...I'd know if someone was grabbing it cos they'd be feeling me up!