Hi John,
Indeed, this is very personal. I consider myself the "Imelda Marcos" of camera bags, I have about eight now
I do have some obvious ones (LowePro Trekker and DörrXL that both pack a two big lense outfit), a really huge one that packs all (ThinkTank airport addicted), a Crumpler that looks like a normal backpack (and opens at the side that is on your back, increasing safety but not very practical...)
Forced by the ever increasing weight and size limitations effectuated by airlines, I have now also acquired a trolley, a 40 euro discount example, best investment ever! It holds everything including my tripod and is 50x35x20 in size. Covenient for transit travel and if you work out of a rental car or have limited walking on tarmac to do. Not so good for for hiking, airshows etc. For that, a shoulder or back pack is preferrable. I have been searching for solutions for a while and some suggestions are:
* buy a normal hiking backpack and some foam inserts
* buy a shoulder / reporter bag (the ones with a large flap) and put some foam in there
* in combination with one of the above: buy some camera+lens bags / use the casings that came with them (I pack my lenses in my Nikon cases and happily throw them in any bag)
There are 'do-it-yourself' websites for above too!
I do not have a high opinion on dedicated camera bags. Partly because they are too expensive for what you get, but more importantly that I lost my 80-400 that was neatly packed in a dedicated foamy camerabag. When the bag fell the lens was bent, whereas my big spotting scope that was loose on top of the bag, survived! the angle under which it hit the ground and the fact that is was attached to the body, were the main culprits. Foam does not stop that at all, you probably need about 8cm thick foam to absorb that kind of energy!
Your concern about 'rob me, I have a big LowePro camerabag' is another one. When you pack gear that is a year's salary in many countries, you are right to try and subdue that
My current 'subdued bag of choice' is a Swiss Army / Wenger. It can hold two lenses in cases and one or two bodies (one of which attached to the lens). I got it for next to nothing in the Lufthansa shop with my frequent flyer miles, so it set me back around 10 euro in p&p cost. Beautifully made and respresentative even for some business applications (front pockets, laptop glove). It retails for around 100 euro I think. Down side is that it looks too attractive to robbers as well probably
Erwin