dissapointed - new LS50w's vs old PioneerFS52's/Luxman R113 - so far Kef's not so great?

People love KEF. I do not.

The LS50s take forever to break in.  There is a dealer in Manhattan who refused to sell the floor model they have because they don't want to go through the pain of breaking them in again.  I have listened to a new pair next to one that is fully broken in...very different sound.  

That being said, bass response stinks.  Those speakers need a subwoofer to be at their very best.  

The problem with LS 50s is they need lots of good power. They don't work well with cheap $1,000 integrateds, at least not in my experience. You need good separates to motivate them to sing, and sing they will when you give them lots of good power. 

The problem with kefs is that they’re kefs. Over rated and over hyped. I would go insane listening to them through the break in period. So much that I would have to sell them before they would get there. 

Unless the 'W' above is a mistake, the OP has the wireless version of the LS50's with built-in amplification, so I don't think the problem is lack of power. 

Personally, I lived with the original, passive LS50's for a year or so, upgraded virtually everything else in my system and added quite a bit of sound absorption to my room, but could never get rid of an edginess that was ultimately unacceptable to me.  Traded them in for more mellifluous speakers (Alta Audio Rhea's) and all was well.  They really should have decent bass, though, down to 40 Hz or so.  I suppose it depends on what level of low bass is necessary for your tastes. 

Some folks really do love them, though. Like John Darko:
https://darko.audio/2016/12/kef-ls50-wireless-review-dars-product-of-the-year-2016/
Have you tried the room correction/DSP?