Ended up getting it - what a gem. I decided to divide up the gear in the following way:
Main Compartment: batting gear I use most frequently, arranged so that I access items in the correct order. So at the very bottom is my helmet, on top of that my current pair of gloves, on top of the gloves is my elbow guard and box. The pads are on either side of the helmet, and have the thigh / chest guards hugging them.
Side Pockets: extra / backup pairs of gloves (I hated getting different pairs mixed up in a wheelie bag), sidearm, balls
Top Pocket: whites, shades, sunblock, headphones (in case I need some pump-you-up music before batting).
Front Pocket: replacement spikes, "medical kit" (tape, spray, etc).
Still loads of space left over. Love it. Only thing is to make sure one lifts / swings the bag safely (in case anyone has a tweaky back). But its much lighter than any wheelie bag i've seen.