I have my Viper equipped with two fixed size 1 beams, a size 2 plasma accelerator, and a size 2 guided missile launcher. It's a rather unconventional setup, and the plasma accelerator takes a bit of time to get used to hitting things with it (Though it's not that hard for me as I played Tribes extensively and hitting stuff with it is not unlike hitting things with a disc launcher), but I can cut through targets at extraction zones, and other players, like butter. The Plasma Accelerator is best at knife-fighting range with a Viper (Which is itself, a fantastic knife-fighting kind of craft), and skillfully used, can disable subsystems of most ships (including the power plant) in just one hit. Against a player in another Viper last night, I dropped his hull percentage by over 60% with a well placed hit, and when he boosted off and tried to escape, all it took was two missiles to seal the deal.
Dual plasmas is kind of awful because their energy requirements are really a bit too much for such a small ship. Plus, with their projectile velocity, it's near impossible to center two of them on the same subsystem and get a hit. I find that the missile launcher compliments the weapon perfectly, allowing for off-bore attacks that don't require any kind of capacitor investment.
The beams are fantastic at cutting through shields; something the accelerator doesn't seem to be very good at. They're also fantastic at taking smaller targets (ie; smaller than another Viper).
Sheer DPS numbers in theoryland or not, when I can take out bounty Cobras in just a few seconds--dropping their shields with beams, and then hammering them with the PAC about three times--maybe just two with a good missile strike added in for good measure), it definitely seems pretty great to me, compared to my experiences with beams and multi's, or bursts and multi's, or multi's and rockets. It just requires a fundamentally different kind of piloting style, with close-range slashing and taking advantage of the Viper's gigantic amount of lateral thrust, placing the shot on the target at the exact moment of intersect instead of trying to fight to maintain a bead. It took a lot of messing around to settle with this particular loadout, and I'm quite fond of its power and versatility after a lot of practice.
