B&W 705s3 vs Kef Meta R3

The B&Ws are mfgr rated at 88db @ 8 ohms; the KEFs 87db @ 4 ohms.  Were they or the other pair you auditioned level matched for comparison?  It wouldn't hurt to bring your own SPL meter into any serious listening comparison.  Generally, the lower the listening volume, the more dramatic the sensitivity benefit

Assuming so, these are large, long established & reputable brands with big R&D budgets.  If any of their products at any above mass-market prices ever sound like there is something truly wrong, there probably is.  Now, I don't mean "the LS50s have almost no 20 hz bass" - I mean when they fail to meet reasonable expectations.  You're doing the store a service by pointing it out.  It's not just a potential wiring issue - the component(s) being auditioned could be faulty.

Just chiming in to add that the magnolia setups cannot be trusted. I honestly can’t believe that many high end brands even sell their stuff through Best Buy. 
 

Maybe occasionally you have one that’s setup properly and the employee is passionate about audio. More likely you’ll get a guy who’s working in the microwave section from 9-4 and then finishing up his shift at the magnolia. 
 

last time I went, the employee hooked up their low budget phone via an aux cable to the headphone jack to play music for me off regular YouTube. I’m also not sure what hardware they use to switch between dozens of Amps and speakers, but that has to have a negative impact on the signal chain. Best Buy is honestly best avoided to audition anything with intent to buy. 

The Bowers has a 10db peak @ 10khz according to Stereophile's measurement.  The Kef has minimal peaking with a smooth "audiophile" downslope in ASR's measurement.  I couldn't find both speaker measurements in either site.

BB has a generous return policy so it is usually safe to bring a product home and try it. Sometimes room acoustics will align with a rooms natural peaks and valleys to offer a uniquely pleasant tonal balance. never say never. 

Given the ineptitude shown by salespeople at our local BB its entirely likely the tweeters in the speakers you were auditioning were fried. I can't say of course that this is a universal problem with certainty, but I'd say the odds are likely. Locally, they are completely clueless.