People who arnt the Eldar hate the starcannon, and to the degree the Brightlance.
And to me it seems like the only options to take, I mean, why bother choose the others right.

What would make these two weapons less apealing but still overpowered like an Eldar weapon should be to make up for fragility and works in the fluff.

What would make the other big guns better?

Play testing is on so I dont want them to ignore the great ideas from the thousands of unpaid play testers with tens of thousands of games played.