I think the "-r" is for their rocker+camber design and has nothing to do with the board being wide or mid-wide.
That said, the Legacy-R is a wider version of the SL-R. It's a great, indestructible board. I'm sure they've changed some of the tech in this board since I bought mine 5 years ago but mine sucks for park: presses are impossible, but I think they've softened up this deck a little bit over the last few years so maybe it's better now.
Awesome on booters, but lacking in the pop & flex departments.
Again, I realize the tech has changed but how does your board hold up on high speed groomers?