The DPS numbers are interesting, but I think the biggest factor is range. You say that the scrambler pistol has roughly the same range as the flaylock, but you try hitting people 50-60m away with a scrambler pistol. You even have the SMG listed as 44m range. That may be the maximum range, but there's also an effective range. SMGs may be able to hit you out to 44m, but only about 1 in every 15 or so bullets will actually hit. Scrambler pistols are also good close in, especially if you can get a head shot, but lose a lot of their kick once you move out a bit because it's tricky to aim it very far. Since the flaylock is an explosive weapon, its effective range and maximum range are one and the same. It's also much easier to aim, and the splash damage ensure that even a near miss still has impact. The flaylock is what the mass driver should be...an effective, mid-distance explosive round launching weapon. A sidearm is supposed to be your close range "oh crap" weapon. It's what specialists use when they're out of their element and what assault characters use when they're out of ammo. Aside from the occasional nova knife boners, I almost never see someone with an assault rifle or scrambler rifle use a sidearm while their primary weapon can still shoot. With the flaylock, I've seen people use it as their primary weapon. That should tell you something in and of itself.