Hardest component to decide on

Digital source are tuff for me, differences are so small and yet so large. I am in that soon to upgrade digital source mode at this time. Could be a long process, for me anyway.

Dave

I've got the same dilema as Spencer with room treatments and WAF. If I kept to the physical chain of the system I'd say speaker cables as they can make a pretty big difference, yet the difference they make is extremely system dependent IME.

Marco

Turntables and phono cartridges because it is virtually impossible to get a demo comparison of even two units on a "side-by-side" basis. Side-by-side demos of all other equipment is easy by comparison.

Mr. Kidknow

Room treatments. It takes so long to get them right and it is very difficult to do a comparison since it's pretty bulky and time consuming to set up. It's probably best just to hire a professional and call it a day -- especially once you get into the "built-ins" (e.g., Albert Porter's configuration).

Close behind in difficulty is everything else ;-)