Its a fact that tweaks may work sometimes but are almost always cash cows with high markup fueled by hype used to help make this ridiculous industry profitable for some companies.
I avoid expensive tweaks like the plague. Similar or better results can usually be achieved for less.
I have not had any recent equipment that I hated. I probably paid too much ($200) for my .5m Harmonic Technology ICs, but these do make nice but expensive amp/pre jumpers on my old NAD receiver when needed.