Depends for me on the situation.
In an Imperial base, facing off nothing but Imperials (Fest), give me that Bryar! Slow, yes, but accuracy and ammo saved is a far greater asset. An E-11 is faster and might do fine if I have a few bounty hunters thrown into the mix as well (Ramsees Hed)
The concussion rifle and assault cannon are good for later levels with multiple adversaries with high vitalities, but they eat up the power cells and are harder to come by then energy cells. All the other weapons, except the TDs, I can beat the game without using.
"The Force is strong with Katarn...." - Darth Vader, Star Wars: Dark Forces