Overrated on RAWK is par for the course.
He's the best defender we have, and he fits the system well, so there should be no talk of selling him or regretting not selling him.
But he isn't 'World Class'; there was a stage in his development where he looked like he could become that, but he hasn't kicked on enough due to injuries, defensive and managerial instability. He's a good player, but has obvious deficiencies, and will need a better partner than Skrtel to come in this summer and take leadership responsibilities.
Agger Skrtel and Lucas Gerrard, as partnerships, have not given us the defensive stability required, and I think it's more down to the CBs than the CMs.