Well, just for giggles, I tried a shieldless Vulture
in a RES. The results were very surprising - initially. After about 1/2 hour taking on singles, I only had a few percent loss of hull. But with those C3 beams, I spent a lot of time waiting for the weapons cap to recharge and did take some module heat damage. While tailing Clippers, their turret beams would more or less bounce off the mirrored armor. The problem came with wings, where whoever you weren't shooting at, were shooting at you. So the first wing, a Dropship and a couple of Eagles, got me down to 81% hull, and my beams were failing. Still, that was only about 15k in damages.
Then I tried it again with E3 pulses. Overall they may have been slower to kill enemies, but there was no heat damage and very little waiting for the weapons cap to recharge. Again, I went about 1/2 hour w/o a scratch. Then I took on a wing of a Clipper and two Eagles. This time they got me down to 83% hull and a cracked canopy. Only 6k in damages, but I couldn't hang around.
It'd been months since I'd been in a Vulture, but I didn't really notice any loss of maneuverability with all the extra armor (as compared to the Python). I was really surprised by how well the Vulture could hold its own. It was also nice not worrying about power management, or pips - just kept 2 in engines and 4 in weapons. But when you take module damage that takes out your guns and canopy, with still more than 80% hull remaining, that's just not acceptable.
I think I'll stick with the strongest shields I can fit, use SCBs to hang around longer, and leave the heavy armor at the station.