The Ruger website says the Bisley trigger is wider (I infer from that they mean wider than the standard Vaquero or Blackhawk) to facilitate target shooting.
I have only seen photos of these models and it is not possible to determine just how wide - or how much wider than "standard" - the trigger is; might any current owner or someone familiar with them comment?
The trigger does have a more pronounced curvature (based on the pictures) and I'm hoping that plus the added width does indeed improve trigger feel and action.
Ned