Don't know about LS 60 vs KEF Reference but FWIW always found speakers placed only a few feet from the walls behind them tend to sound flat imaging wise (probably with enhanced bass) whereas a monitor speaker usually had greater clarity and 'depth' of image when placed out about 4 to 5 feet from the wall but with some loss of bass (unless you found a bass node to set them in). That's the reason many folks use subs with small speakers. Try placing the 60's in the same place you have the Reference's and see if it sounds better (to your tastes) than so close to the wall. Its a trade off that I would vote for even if I had to get subs to flesh out the bass.
KEF LS60: Distance from wall behind them
I'n most of the video reviews of the KEF LS60 I've seen, the speakers appear to be quite close to the wall behind them. I realize they are not rear ported, but is there a recommended minimum distance from the wall behind them. They will be replacing KEF References 1s that are 45" from the wall behind them.