Agreed on killshooter for everything....
As far as 88s go, I have killed more fighters than bombers. I was a mortarman by trade, so I was able to pick up the gist of the fuzing and trajectory pretty fast...
Is it easy? No. But, when you are surrounded by the Annie Oakley AI Base ack, you have several metric tons of ammo, and Speedy Gonzales aiding your reload and proximity setting speed, it's a little ridiculous.
Fighter vs. 88, sure... fighter will most likely win. If he has ords and/or knows what he is doing, you'll get one shot at a high rate of closure.
On the other hand, if said fighter is in a dogfight 2-4k away you can sit and lob shells with impunity. While I got less kills against fighters at this range than against the point blank timed shots on guys racing past the base (VERY easy to kill even high deflection fighters this way) I certainly wildly altered the latitude of their fights by popping near them. Crippling a fighter is just as bad as destroying him outright as far as this goes.
The other issue is that with bombers you are almost always tracking them in the vertical arc... with the sun in your face half the time... and once they pass over, you have to wait a ridiculous amount of time for the gun to traverse the horizontal. When you are tracking a fighter who is already engaged, depending upon their distance, you only need to traverse within a 10 to 30 degree window for the duration of the fight and that is no problem at all.
I stopped using 88s, and for the most part I only see them used by either people I have shot down trying to get revenge, or as a last ditch crutch against poor defensive planning (i.e., I spend 30 minutes climbing and vectoring onto target and 88 gunner starts lobbing shells ~4 seconds after manning the gun).
Luckily, the vast majority are absolutely atrocious at using the gun. the point is that with a little practice a player can turn these guns into unrealistic and wildly non-historical "I can't do it in the air, so let's lame it up!!" guns.
And before you call me a furball whiner or whatever, go take a look at my amazing fighter stats first.