As to subs being difficult to integrate, I must have just gotten lucky (you can look at my virtual system). My Kef R400b sub perfectly compliments my R11's, which i believe only go down to 32Hz. I run the mains full range and cross over the sub around 60Hz. It fattens up the bass guitar and gives the kick drum and lower tom toms a little girth.
I can't tell where the sub is located in the room if I close my eyes. I also don't feel like I need another sub either, as I've heard multiple subs is preferrable to one sub.
To each their own. I happen to enjoy the music with sub added. YMMV