id say for me aquasoil is probably worth it if you want a really full lush tank. you wont have to worry too much about fertilizers. but it tanks longer to cycle i hear. i dont think capping aqua soil is really necessary. they have some lighter colored ones but the chemicals inside might be different im not actually sure. i know there is africana amazonia and one more and their colors are all different. soil obviously trumps because it gives good space for roots to grow and also feeds directly to roots. sand has no nutrients but has the ideal porosity for roots to grow. then the stuff you find in most regular aquariums the gravel stuff doesnt really do well for plants because its harder for them to root in. but you should tell us the size of tank you're working with. also what plants you're looking at and what fish you're looking at as well.