I think the balance is quite nice. Right now im using a Corvette in Haz and i rather attack an FAS/Clipper/Conda, and not just because they pay more, but they are actually easier to kill. Something like an Imperial courier/Cobra/Vulture can be very irritating, and can sometimes take longer to kill than just going for a much bigger/stronger/tougher ship. So I see a balance here, and generously geared towards small ships. In reality I can vaporize those little suckers in just a few seconds, but its very challenging getting my guns on them for more than a few seconds, especially when its a cmdr, I've had some get behind me and pretty much stay there for most of the fight, even when using the reverse maneuver/FA off, so skill does play a big role here. Turreted weapons are also nicely balanced in favor of small ships, not only can chaff be used to counter them, but they do so little damage that you might as well open the cargo hatch and throw sticks at the other ship. In other words, if you want to take down a good Vulture pilot, you will need more than just turrets, you will actually have to get this agile ship in your line of fire at some point, which isnt easy using a slow lumbering ship.
Also there are already plenty of people in Vultures/DB/Couriers taking on Conda/Corvette pilots and in many cases winning. So if you have enough skill, you can actually take on an opponent who technically has a huge advantage over you. This to me says good balance. And between two equally skilled pilots, lets be honest, a small assault craft, with small guns should get its ass kicked by a big assault craft, with big guns, just the way it goes.