My friend just traded in his LS50's.
His room is average size ,he listens at moderate to low levels,and nothing he listens to has large scale dynamics.
He also listens in the near field and he has added room treatment devices in the corners and first reflection areas.
I thought the Ls50's were very good in this room.
I also thought that the MMG magnepans also sounded great.
But somewhere in the few months he owned both(never broken in I think)he felt they both lacked body or were a bit tipped up in the treble.
Someone mentioned the LS50 were tipped up in the upper frequencies(I wouldn't say that from what I heard)and so that's what he always heard from his system.Too much treble.
I thought the Kefs were good and ticked all his boxes that they would have been his last speaker.
Alas they were traded in on a pair of used floor standers that he felt was better.
Then he traded in his integrated for a new pre-amp power amp set up, and then traded in the power amp, next he is thinking about speakers again.
I never felt my friend needed to add a sub but I've never heard a bass heavy sound from his system(WAF).
Still for my tastes(panels,large full range stats and Tannoy HPD)I was quite pleasantly surprised by how much sound the Kefs project, and how coherent and balanced that sound was, similar to panel sound.
Maybe that was the reason he didn't like them, he's not into panel sound,but prefers cones, and coloured cones at that.
Never heard the Monitor Audio, but I can say that the LS50 and all the hype surrounding them,were one of the finest cone speakers I've heard, regardless of cost and size.
In my book, they would have been a keeper,and upgrade the rest of my system to their level.