I don't, I like the regular shotgun more. I just feel forced to use the double barreled one because it's more powerful (it's 2,5x more powerful than the regular one at close range, even though it only uses 2x more ammo).
I also like Doom 1 and Doom1 style wads much more than Doom2's.
The worst there is in Doom 2 style are the city maps. There are a few in Memento Mori (which I mentionned earlier in the thread and which I haven't finished yet) which are just terrible. If I want to play city maps I'll just play Duke3D.