I don't like the mercury in my mouth either, but this last crown was such a hassle, ending up being a root canal...I think I will wait on replacing the other amalgams.
I found out there is some value to the sharpness of the ridges of the natural tooth. Ceramics don's seem as sharp. I didn't realize this would matter in a molar.
The good news is that it would seem like dentists are using ceramics now, they don't put in Amalgams anymore. That's a relief!