i choose good knowledge, because i am comfortable setting up my system, usings a meter, and properly placing speakers... but i am by no means an expert, subs and sub placement are my weak areas, primarly because i dont own a sub (next on the list, however new TV may take presidence)...
most enjoyable thing about A/V equipment is relaxing and listening... i am not a tinkerer, but do occassionally get biten by the upgrade bug... i have been using Paradigm Monitor 9's for like 6 years now with a Marantz Reciever...