"In the next explosive issue of Boltgun Monthly, we take a look at the famed Storm Bolter. So, how is it? Amazing? Crap? Best left for Grey Knights and vehicle pintle-mounts? Tune in to find out, or we'll show you."
Personally, not being militarily-trained, or even so big into guns, I've never seen the big issue on this, between clips and mags. To my unenlightened mind, they are the same dumb thing, each for just a different scale of gun. Is the weapon chain-fed? No. Nuclear-powered? No, then some sort of bullet-holding container must get plugged in. Is it drum-shaped? Nope. Then it's a clip/magazine. What's the diff, semantics aside?
Now I'll probably get the real answer to that question, but maybe I'll learn from it.
I know that they exist in other books, most of which I have, but I really do, sometimes, wish they'd make a more comprehensive Critters book. So in OW, the Guard fight Chaos (who doesn't?), Orks, and Dark Eldar. Maybe I want to use "regular" (Craftworld) Eldar, Tau, or something. I know they try to stick to the setting, and don't include numerous things that don't occupy it (the one place they choose NOT to copy/paste from the other rule books), but sometimes I want to imagine them someplace else, fighting the Nids of Hive Fleet Leviathan, or the Tau, and not wanting to have to dig up the DW books, then the errata, for the better gun stats, and THEN do the converts between DH1/RT/DW to OW/BC. Maybe they aren't So big of changes, but maybe I AM COLOSSALY lazy.