There's nothing inherently wrong with hydroton. It is a wonderful medium if you treat it right; it MUST be pre-soaked to pH 6 before use, just like RW. Silica content is interesting but I just get around that by running a foliar of Silica Blast up to about week 4-5 of flower.
Also, if you are using RW plugs in a HT bed, they should be sunk only partially, and set ABOVE the flood level in your table, because they hold so much more water than HT that the bed will be dry but the cubes will be soaked and you can get stem rot. FYI.