To address the original topic, fighters are good for lots of things.
You can make them easier to construct by reducing the hull cost from
ten times the hull size to maybe five times. Then, use them in the classic "swarm of ants" fashion and they can be quite deadly. I think they are a bit vulnerable because of the short range of their weapons relative to ship-based weapons but this is where the numbers come in.
As for the other topics that have cropped up here:
Missiles and PDC are a problem. Since the AI is not smart enough to adjust its ship designs for the opponent it is facing you pretty much have to put PDC in the default designs of all AI ships. But this then makes the AI races designed to favor missiles very weak in the mid and late game. I hope, since MM is finally adding new features to the game, that a way to increase missile ECM will be added, or maybe even special capabilities like multiple launches in a single turn or something. We shall see.
PPB and other weapons: Yes, the PPB is a very nice weapon. Now that the Emissive Armor function works correctly every race has an effective counter-measure, not just the Organic and Crystalline tech races. When you run up against someone using PPB research Emissive Armor if you haven't already and cram your ships with it. Phased shields are an option too, of course, but more expensive in research points.
Even so, weapons are not everything. Superior tactics and just over-whelming numbers can beat any technology. I don't think the PPB is anywhere near as unbalancing relative to other weapons as the PDC/missile problem. At least, not for humans. The AI of course cannot cope with anything.
[This message has been edited by Baron Munchausen (edited 25 October 2001).]