so had 105 sd’s, ritchey WCS echelon and have just purchased some look keo carbon blades.
Firstly, there all as easy as each other to get in and out of, and the cleats look similar. Ritchey pedals were lighter than the 105’s, lighter than dura ace in fact. Great pedal but bearing only lasted 1 season on 1 of the pedals. 105’s have been on the commuter and winter bike and have had no issues with them. Still smooth bearings after 4 years, replaced cleats and thats it. Aesthetically though not very pleasing and weigh quite a bit.
Only had the looks for 3 rides now but click in is very positive and seem fine in use. Light compared to the others and offer better aerodynamics. Time will tell.
So, in summary there all about the same, no real cons to speak off, its all a matter of how much you are willing to pay and if you want the extra weight penalty. You cant really go wrong TBH