I have the 2011 El Mar 26lbs witha Reba stans 355 tubeless Sram x7 & x9 2x9 Salsa promoto flat bars aluminum and a 21lb Mamasita setup with a Niner carbon fork & xo 2x9 salsa promoto carbon flat bars.
all I can say is the Mamasita is faster where it needs to be "climbing"..
I also do endurance racing and that is where the Mamasita shines this bike is a race bike. Now the El Mar is also going to be used for racing on a few laps of a 24 hr race while the other is being cleaned.
The El Mar is my go to everyday mtb ride so if I could have only one It would be the Mamasita but if I quit racing it would be the El Mar.
So to the OP, how much endurance racing do you do? and how well do you do at it, are you say in the top 10, if you are and want to be in the top 5 then too hell with comfort your not going to get it unless you go with a FS 29er, don't get me wrong here, my bikes are comfortable but not after 12hrs in the saddle. If it was me and It's more about racing,, then the Scott is what I would get between the two.
one more thing gearjunky said it " A steel frame may flex a bit more than aluminum, but I couldn't perceive a difference" that is my experience. Also the El Mar is not a flexy steel bike like.