i felt SS could be situational depending on the composition being faced. if the enemy has no purges and you know they will train the ret, SS helped keep the pressure off a little better than selfless healer. with no purges you could rely on your hand spells keeping your healer alive more than SH, and not having to put flash heals out gave a bit more GCD for offensive abilities.
having said that, mage and hunter seem to be a member of every 3s team in the 1750 ranges so the circumstances for it were seldom at best. But i am not a fan of having the choice of talents made for me due to the other 2 choices on the row being terrible. having Glyph of Word of Glory double its duration when used in conjunction with EF would make me consider it, for example.
SS absorbs like 20k before battle fatigue for ret, it's shit