Shown below is the Really Right Stuff BK-1 L-Bracket for Pentax K1 on the Pentax K-1. Nice touches include the anodized finish and the laser-engraved centering marks.
Like all L brackets, the dovetail allows the camera to be instantly mounted into a compatible clamp in either portrait or landscape mode—no flopping the tripod head.
I like L brackets for another reason: the bottom and left side of the camera are protected from scrapes and dings. I almost never take the L bracket off my cameras. Most models allow just the base plate portion, in case the “L” is not desired for some reason, but in general I recommend the full L-bracket approach.
Really Right Stuff offers a very wide range of L brackets for just about all brands and models (I use their plates on all my cameras, as well as my favorite tripod, the TVC-24L). The RRS camera plate designs are almost always optimized/customized for each camera for a perfect fit, sturdy and robust yet with minimized weight.
Shown below is the Really Right Stuff BSL L-Bracket for Leica SL, a custom design that fits the SL perfectly. I used it briefly before I had to return the loaner SL—excellent bracket.