I have owned seven different Buckmarks over the years, down to a couple now, both are GREAT guns and have been for a very long time ...
BUT
Shot a few rounds through a buddy's Mk IV 22/45 Lite, got one for myself to put some serious round count through and ... well ... total of 4 Mk IV 22/45 Lites later, I gotta say that Ruger has that platform well figured out.
Bone stock, Browning has a slight edge with the stock trigger but loses that edge with reliability issues. If both the Buckmark and 22/45 have some quality aftermarket goodness installed, the Ruger is a much more accurate, more reliable, less finicky shooter than Browning could ever hope to be.