Can a set of Ls50 metas surpass or equal a set of Kef blade metas with subwoofers

Probable not surpass or even equal, but your setup looks like it would sound very good.  One of the big points about the Blades is the full range dispersion pattern which your setup lacks.

l researched the blades and stereophile said the UNI Q module was crossed over at 300 if l read correctly..

The blades crossover from the woofers at 300hz based on measurements. Kef claims 350hz.

Those are, I believe, all in reference to the original Blades and not to the newer Meta versions where the crossover has been raised to 450Hz, according to KEF.

I've tested my 8 inch subs...they will play upstairs in the 100 hz range quite nicely...lm very happy with the results..lm sure a set of blade metas and a six pack of Rel subs would do a better job...lm just so impressed what a 1500.00 dollar LS50 can do with subs..

I agree, based on my experience,  it’s objectively hard to beat ls50 meta and even a single well integrated quality sub for good sound at spl levels most people would typically want. It can be done but not easy especially for the cost.

Having said that, subjectively one never can be sure what will tickle another’s fancy best so that is a totally different story.

I just switched from a pair of LS50 Metas with a pair of KC62s to LS50W IIs with the KC62s. I think the KEF DSP app does a great job of speaker-sub integration, better than I did. This is my first venture into powered speakers, so I may keep Metas or Magnepan LRS with ultraRendu and Ayre A7e as backup.

My primary setup is Reference 1s augmented by a pair of Velodyne HGS-15s, with Ayre 5/Twenty series electronics. I’m wondering about replacing that setup with LS60 and KC62s. I listen mostly to jazz and classical streamed by Roon at moderate levels. Any advice?

db