This is it...
My personal thought is that it's too damn big... If you want to carry that much stuff you'd be better of with a rucksack style bag than a shoulder bag...
I love crumpler bags though... I have an old 'Bunnyman' that I carry day to day with K-x with tamron 17-50 attached, 3 more lenses, flash, triggers and 2 sets of spare batteries and it still has space...
I have a muffintop 4000 too... but rarely use it these days... Cracking bag if you don't need to carry much though...
Also have a lowepro flipside 300 that fits all my DSLR gear and an MEsuper, fuji p&s, waterproof jacket and pants, and tripod that I use for travelling,walking,cycling etc...