Clear difference between Harbeth 30.2 & Super HL5 Plus?

Okay another question for this group.  I’m really struggling to get my Harbeth SHL5 plus to wow me.  I’ve had them for about 3 years and have them plugged into a Line Magnetic 501ia tube amplifier (100 w).  It just feel like I’m being pushed into the midrange frequencies of songs and missing nuances in the higher range. This surprises me given it’s super tweeter. Even the mid-ranges just seem slightly muted or muffled.  
I so want to be wowed by these speakers like I was when I tested them.  
I was told by another person who has these speakers that he has been blown away and seemed to attribute some of that to having a very nice solid state amp.   
I listen to mostly rock, post-punk, new wave and classic rock but also enjoy jazz and classical.  It’s the former that I’m struggling with as the jazz and classical seem to present well with these speakers.  
Thoughts?

Firstly thanks for the offer.  I may still take you up on the offer to hear the Luxman. 
You are absolutely right and it took a failure of my LM amp for me to be pushed to do something different.  I now have a PrimaLuna EVO 400 and it is night and day.  Now all of the aspects of any music have seem to come to life. I hooked the new amp up yesterday and didn’t leave my music room for 5 hours.  No listening fatigue, just pure bliss.  
I ran the first 2 hours without a sub and was exceptionally pleased.  I then attached a new REL S812 and it took the entire soundscape to a new level...from one that was already exceptional.  
Thanks for the encouragement.  This far I’m hugely pleased but may still want to hear what they sound on a superb solid state.  Thanks!