yep, I don't get it either. I've had great results with S-23. Just used it for a Vienna Lager recently, and turned out pretty much how I wanted it- clean and malty. I've heard people talk about S-23, but haven't experienced it.
But as always, YMMV. Maybe I've just been lucky. If I had seen...
Mine's super easy:
5lbs of pilsen DME (or equivalent LME)
.25lb carapils
.25lb crystal 20
1 oz hallatauer 60 min
1 oz liberty 20 min
US-05 dry yeast
Ferment cool around 66F. Let it sit in the primary for 3 weeks, then keg and serve
Sometimes just to be a little different I'll dry hop it, or...
Yep, I usually add 1/3-1/2 my extract right at the end of the boil. Never had a problem. Definitely helps with hop utilization, and color. Hadn't thought about the head retention help, but I can see how that might be.
Cheers.