UPDATE: Well, yesterday I finally managed to kill something with the 17-lb'er, but it was an incredibly frustrating exercise. For one thing, everytime I fired, the gun settled in a rather random place afterward. This meant I had to take time to very carefully note my gun elevation prior to each shot; took quite a few shots to walk it onto the correct range. It took me three of four pings to kill him, too (a Tiger, so I suppose that's to be expected). And yes, it has an actual gun site, but the ballistics of the weapon seem to be worse than the 88 (more drop, even at relatively short range). And as noted, SA is awful and traverse rate is snail-slow. Still nearly useless, IMO.
I agree, there are better choices for battery artillery, but the 17-lb'er is as close as we have to a real arty piece (although the 88 is also capable of fulfilling that role). BTW, anyone know how to adjust the burst range of the 88 when firing AA rounds? Default seems to be 5 K.