Legions created a problem for us because at the time small sets had 55 commons, 44 uncommons, and 44 rares
Commander tax is an additional cost while affinity is a cost-reduction mechanic, and additional costs are applied to a spell before cost reduction
It makes one creature incapable of blocking, which doesnt really have an effect in Commander, makes the Ring tempt you, which is okay but uninteresting (more on that later), and it tutors a Mountain onto the field
A clear advantage is that if you have bigger creatures than your opponent, you can get real stompy
Ruthless Regiment isnt far behind
Deathtouch creatures make every combat step a dangerous proposition, while your removal keep opponents on the defensive