You really shouldn't be dissatisfied with average recordings, some will sound better than others but I haven't come across really horrible recordings except for the original CD of Jeff Beck's Blow by Blow, the SACD is the best sounding so far.
I am not familiar with the NAD Series you have, never heard them. Do you think they are detailed sounding?
None of my buddies have the CSS Criton 2TD-X so haven't heard that speaker either. I usually love silk dome tweeters but the LD25X does have a rising high end. This speaker may sound better pointing straight ahead instead of toed-in.

Detailed electronics along with speakers can be too much of a good thing, sounding excellent on state-of-the-art recordings and not so much on everything else.
These days I prefer the RAAL tweeter, it is detailed, smooth, fast and doesn't have a rising high end. The difference in sound between a silk dome tweeter and a RAAL is like comparing a Ford Focus to a Subaru Outback, both get you where you want to go but the latter is much more comfortable on every road and off road, not just the smooth roads.