I'm doing a killall playthrough right now and since it's a bore to just kill everyone I want to kill people faster, so for that reason I modded in a custom GMG and Ripper so it'd be easier to do things.
But that's just cause I do a killall playthrough, I don't see the fun in having SPECIAL at all10 for a 'serious' playthrough. :/
To make things go faster and to make the game a little more interesting, add a dozen or so Gojiras to the game via the console, then set them to be friendly to you. They sprint around the map killing everything in their path, and even if something does manage to kill one of them, it will just respawn. I found all of this out by accident during a mod test playthrough, when I tested some weapon mods on ~10 Gojiras. Long story short, I would often arrive at a town to find everyone dead, and occasionally I would arrive somewhere and find 3-4 Gojiras toasting everyone in sight.
Oh, and if I may suggest a grossly overpowered GECK weapon to try, I would say to make a special version of the Laser Detonator from Lonesome Road, a version that does 200 damage per shot and that doesn't have the effect to only work on warheads. I've always wanted to try that, but haven't needed a grossly OP'd weapon as of yet (since I've had the game for PC that is, I could have used it on my PS3 kill 'em all playthrough).