Really ?, I was underwhelmed when I finally got the gauss rifle. It had a nice animation, but it took way too long to reload, didn't zoom very far with the scope, and low damage compared to what you could get with guns and a number of damage amplifying perks like 'Cowboy' etc, and the thing used 20 MFCs per shot if I remember. Hard to find enough to keep going.
Since you can't hit anything in VATS outside of 20 meters a better bet is the sniper rifle or marksman carbine. Anti personnel rifle for very resistant targets. More shots on target means more criticals.
You can get the plasma defender very early in the game and it's the only thing that redeems energy weapons. You won't find better. Or rather, when you do find better they gobble up all your ammo in a heartbeat and you are back to using your backup weapon.
By the way they should have made the flamer cause frenzy and panic. A bit of a letdown to see a raider on fire carry on like nothing was out of the ordinary.