Someone who I know that has heard the LS50 (maybe owned it) and now has bought the KEF R3 tells me that it has much more bass than the LS50. He likes the R3 a lot more. It is also not expensive if the OP sells the LS50. The R3 is something like $2K.
My plan is to use the new KEF KC62 + the Reference 1 (or R3).