Also a good pump can use an extensive range of ammunition types with no change in reliablity where that is rarely the case with an auto.
Lets say agruendo that this is the case ( I don't think it actually is for all autos). For HD this is not a huge consideration. You load it with slugs or buck and whether it will run 7/8 oz target loads or the like is neither here not there.
As far as practical goes, a good quality pump is much cheaper than even the cheapest auto.
Pumps are cheaper that goes without saying. However, cheaper is only one consideration of many when it comes to being practical. How hefty of a consideration depends on ones finances. For some a few or even several hundred dollars one way or another is not much of a factor at all.
Basically, a pump will get you in the game cheaper and easier.
No argument there. I'm not sure that it equates to it being per se more "practical" than an auto loader. I'm certain that doesn't per se equate to it being the better fighting gun.
I like the fact that I could carry a selection of loose ammo and be able to feed my gun as needed.
I find truly loose ammo to be more difficult to carry and access than a loaded mag or the 5-10 round variety.
Of course, you could carry a couple of 10 round magazines on you and that would probably be enough for pretty much any likely scenerio any civlian would find themselves in.
If we hypothesize (fantasize?) a scenario where 20 rounds doesn't suffice that is not an argument against the saiga and its box mags it is an argument for them IMHO. My 930 SPX for example is an 7+1. I could ghost load it to 9. However, I, like many, would keep it cruiser safe. The gun has 7 rounds in it. With even an 8 round side saddle (and some pump guns wont run that without modification) and a two shell holder a fore the ejection port I have only 17 rounds on it. A pump might have an 8 round mag tube and an 8 round side saddle. If you need 20+ rounds things are not looking good unless you have an additional source of ammo you are going to carry. In which case I doubt it is vastly superior to carrying it in a box mag.
Some people keep spare mags in a "sneaky bag" right by the gun. My set up is a three mag pouch, "man purse" bandolier of sorts. I can sling it over my shoulder in less than a second and have 30 more rounds.
As the round count climbs the reload speed and, as importantly in my mind, simplicity of the box mags starts to be a much more significant advantage.