Ceramic varies a lot, some of it is used as body armor.How would it disintegrate? As hard as the stuff is, and as low (relatively) a flow rate is through it, it will last us, our kids and grandkids lifetimes.
We have a dam (420') with 3 18' diameter discharge tubs putting out 10,000 cf/s of water, ceramic lined. The COE said it will last 100+ years.
biomedia probably isn't going to disentegrate though. Plus, you've probably got far more surface area for bacteria than you need (especially in a planted tank) so it doesn't matter if the pores get clogged.
If you do want to replace it/buy more biomedia, there is no reason to use the eheim brand. Get whatever is cheapest.