I didn't switch per say, but have grown plants in Schultz Aquatic Soil, Pool Filter Sand, Seachem Onyx Sand, Fluorite and ADA Aquasoil II.
I can honsetly tell you that as far as results and performance go ADA Aquasoil II gave me the best results, even where I used plain compact spiral compact bulbs for lighting and DIY c02.
The biggest difference I found was that with ADA As II balance seemed to occur right off the bat as evident by lack of algae and superior plant growth. However, the gap seems to diminish the longer time passes with planted tanks using other substrates, so long as you do everything right(sufficient and consistent c02, moderate lighting, regular maintenance, and water column dosing) in the long run you will see comparable results as that of ADA AS. The question is, how many people are willing to be patient enough and battle through any issues to be rewarded after many...months with a good algae free tank. With ADA Aquasoil, you still have to do the right things but in my experience, superior plant growth and balace leading to an algae free tank just seems to occur sooner, at least that is my observation comparing ADA Aquasoil grown plants vs plants grown in other substrates.