Fastpack 200 is my first proper photo bag. I fit there Nikon D90 with one of the three lenses attached, and the other two just fit in two compartments. Third compartment I use for reg size flashgun. Lenses are: 50mm prime, zoom 18-70mm and big telephoto zoom. Camera is conveniently and quickly accesible like in a slingshot.
The bag houses this stuff very snugly, but it could be a little taller, so that the fast opening would make access to the items on the sides more convenient. Also the flap does not align perfectly with the bag body, but this is dismissable. The bad thin is that the zip end a bit too soon when fully open, and the flap really insists on closing by itself.
The camera compartment has detachable pads with velcro mounting, but customization is limited by scarce location of places where you can actually connect the pads. Still, you can shuffle things around a bit.
Anyways, the bag sits nicely on my back, straps adjust easily, access is convenient for the cam, but do not try to change lenses while the bag is hanging sideways on your shoulder ;) Finishing is very good, bag seems to be able to withstand a lot. Top compartment is OK, remember that this bag will not allow you to carry A4 sized papers unfolded.
If you can - see the bag in reality and compare with similar for yourself before buying here.