Ok, enough of that tosh, the AI is totally buggered. I should have lasted no more than a few minutes. I peppered one a bit, broke off expecting to find the usual horde on my tail. Nada. Picked up another and gave him a good pasting, enough to put him out of the fight with a smoking motor. Looked for the others, they were 2500ft away, going in a big circle (four of them). The one I'd originally peppered made a desultory head-on pass, so I chased him again. The four that had been way off in the distance, they came back and paraded across my nose like I wasn't there. I gave one a good kicking. Then one came from behind me and passed over me so low I nearly had a heart-attack, but he didn't fire his guns.
Basically they behaved like I wasn't really there, or that I was an unarmed civvy and they were just mildly interested in checking me out and having the occasional squirt for a laugh.
Olham, I'm not sure what difference clouds-5 makes. Maybe a bit more complex (more opaque bit-maps to fly through). I've got it on five because it has no appreciable impact on my fps that I can see.