ok in the game, its not as powerful at a distance, though still more powerful than a normal shotgun, or even a Double shotgun (minumum damage, of course!). at point-blank range, though, its basically a BFG on steroids! but remember, once the triple 10-shell belts are fired, reloading the belts takes 3x as long as a double shotgun, or 6x as long as a normal shotgun. and there are no "versions" of this to reload faster! the worst nightmare of a player using this is 3 or 4 Pain Ele's spawning lost souls every other turn! no way to run, and any chance of dispersal is nullified by the fact that most of it will hit whoevers closest, and that which doesnt isnt gonna hurt those sheer numbers! a normal player, facing that, pulls out his trusty BFG, and they ALL die. our shotgun guy is dead. period. even 1 PE can screw him over. and so can AVs if they have anyone between you and them. the cyberdemon isnt a pushover, either, cuz his armor takes the brunt of the HE part off, and even if you can get right in front of him... well... he may be huge, but hes not a fatso. at least a quarter of the pieces will end up missing, or going between his legs!
as for real life, its designed to be used by explosives specialists (they already have explosive stuff on them, and HE shotgun shells arent very explosive compared to anything else except gunpowder!) as a field weapon. why? at point blank, the Thundercracker can probably deliver almost as much force as an AT rocket! in other words, it will quite likely blow a hole in tank armor! and its easyier and faster to use than plastic explosives or C4, and shotgun shells dont get unstable and blow up because some clumsy oaf drops them!