The 1/5th is kills & deaths combined. And I absolutely do not see a Ostie for every 3 Wirbs.
Generally spoken, Osties are a bit more prevalent at VBase defenses, where you can expect some low to medium alt buffs attacking. You can almost never see them defending airbases, or rolling to a town to fend off CV planes attacking it.
Perhaps thats whats affecting my perception. Since I'm usually at Vbases, I'm probably seeing a skewed sample of flack ratios.
And I have the same problem: 1 round is JUST under his nose, the second is to the left of the cocpit, and
damn, my turret's out. well thats inconvienent Even so, I find the osti is more usefull, as even one round will kill most planes. There is a lower chance of hits, especially at long range, but even one hit is likely to be fatal.