Very nice mix ERJEE.I thing you did very good work with esses!i like very much your back vocals too.
p.s. you remind me the tambourine...i didn't use it at all in my mix, in fact i forgot it..
Around 1:30 when bass and guitar play in unison, it sounds a little out of tune together. Maybe some effect on guitar could fix that, so that the bass and guitar could be more separated.
Guitar solo is little bit shy and small
I agree with gopener: nice effect with background vocals.
And those esses are not problem to me. But if you still want to tweak out one es here and another there, do it by hand with clip gain line. That way you can choose exactly how much and which es should be tamed.