Yup no fatigue with old Ls 50s and not expecting any with the metas either based on limited audition and reviews to date. 
I’m going off of memory but I believe the original LS50s have a bump around 12k that could be bright to those under the age of say 35. 
I haven't heard the meta yet but I found the original LS50 to be fatiguing because of the extra energy mostly around 2k, I applied a few filters based on the Soundstage measurements to make them more neutral and they were amazing with no fatigue. 

The new meta LS50 have detailed measurements in their whitepaper and they appear to be much smoother in the highs with no peaks like the original LS50 so I wouldn't expect them to be fatiguing at all . 

Hi all,

I just bought a pair of these speakers.  I have $3k to spend on the rest of the system - what are the recommendations?  Should I go the Naim/Cambridge/NAD route, or should I go separates?  I enjoy critical listening, but most will be casual with the speakers in my large-ish office.  I used to have a krell monoblock system so I appreciate good sound.  Would be nice to get as much as I can.  

 

Thanks!

Still loving mine. Planning to try out a nad m33 soon to see if it can replace what I have. Expecting it will do just fine with the KEFs in the smaller room ( see my system pics) but my big Ohms in  the much bigger room where I tend to go with higher SPLs from time to time will be more of a challenge. Replacing 500w/ch with (only) 200 but hoping that will be good enough. We will see. The m33 is currently on back order most everywhere it seems due to microprocessor chip shortages.