B&W 685's Vs KEF LS50

I recently picked up a Peachtree Nova 300 (an amazing integrated amp IMHO but thats another story) and am running it against B&W 685's with great results.
Q: I'm wondering if the KEF wired LS50's would be an improvement to the B&W's?
The ls50 would be an improvement in refinenement and tones,  but you may end up trading one 685 good quality for a ls50 good quality.   Like mzk says, you would get more out of the r300.
The Peachtree Nova 300 output with either of the speakers you mentioned I would never had considered.
The Nova 300 has an 300Wpc into 8 ohms (24.8dBW), 450Wpc into 4 ohms? Heck of a source powering speakers that you have or are considering. I’ve always been a B&W user, with that Nova 300 I wouldn’t have considered anything less than the 703 S2’s or something comparable to their specs at a minimum..
Wanted to add to my previous post: prices today and what you’re trying to do factors in most. Budget wise, I would look for a high sensitivity speaker setup to run with that Peachtree if you’re not into loud in your face type of music. Less sensitivity speakers require less power whereas high sensitivity require more power. *ie, 150-200 watt 95db speaker with that Peachtree would sound awesome with a small to medium listening room, you don’t need new or the best. Only thing you have to remember not to get alcohol ears and crank it up...*laffs
I apreciate all the feedback, just to clarify, I had the B&W 685s before the Nova 300 and realize they are small for the WPC of the Nova 300 but the clarity and sound stage is remarkable, especially with a decent sub in my medium sized room. I'm trying to stay under 2k if I upgrade but could be talked up to 3k. 
B&W 700 S2 or something like it is on my radar but I have heard remarkable things about the KEF LS50s and was curious.
As Chris R said it's probably a case of too close to be considered a real upgrade
I believe the LS50s are an upgrade over the Bowers 685.
I have owned the 685s and enjoyed them paired with the Peachtree 150. I now own the Kefs LS50s and they offer an incredibly focused 
soundstage and razor sharpe imaging. However the Kefs are not everyone’s cup of tea so YMMV. Everyone says the Kefs need lot of power, this is true - you have that in the PT 300. At the current price of $999 the LS50s are now quite the bargain. I suggest you buy the Kefs online from one of the dealers that offer a 60 day return policy so they have time to break in and compare them to your 685s for a period of time to actually hear what works for you.

Bingo, that's what I suspected but needed some empirical data. I hadn't thought about the return policy idea, I'll look around and see who has that. Cambridge, amazon?
I think paired with a sub this might be a perfect fit but it would be nice to get a test drive
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Crutchfield or Music Direct both have a generous 60 day return policy.
Try a Rogue Chronus Magnum integrated amp on the 4-ohm taps with real decent weighted mass speaker stands with your 685s.