I've been lurking around for awhile...guess it's as good a time as any to get my feet wet...
My Father in law owns one from his SASS stint, and I got to play with it for a few weeks. (Lost interest within a few days though)
I found it to be a foul, crude, morphodite abomination of a weapon. To compare its action to a cement mixer would be unfair to the cement mixer. The trigger was heavy, and the feeding was inconsistent. (And thats without adding in a jingoistic political speech)
Whether you "could" hold the trigger down and fire it while racking the pump is irrelevant, I could still empty my standard old 870 much faster just because of the problems with smoothness. I suppose one could say I'm making an unfair analogy comparing two pump guns designed during such different time periods, but the original 97s I've handled and the similarly designed Marlins from back then are MUCH MUCH more acceptable.
Hypothetically, I suppose you could get one, take it apart, and spend twelve or fourteen hours going through it with some fine grit sandpaper, a Dremel tool, and some polishing compound, but even then I have my doubts. Afterall why waste your time polishing a errr....ahem.....piece of fecal matter that can occasionally be found on the back of ones shoe...
My experience wasn't a pleasant one, but if you're hell bent and determined to pick one up I know a crotchetty old man that'll sell his for cheap...
Hope I could shed some light on your query since I've had the (mis?) fortune of pragmatic experience with one...