Don't know where you were looking into iAVs, but there never has been anyone trying to sell anything associated to iAVs. Poke around ..... See for yourself. http://iavs.info/what-iavs-is/
And as to trying other things, I've been there. Gravel based F/D which worked ok initially till a year or so later when everything started going sideways. Had enough chasing filter issues, siphon issues, chemical testing, etc. Since I got my iAVs up and running I can't understand anyone wanting to stay on the dark side ..... guess some people need to take their blinders off and look around. But ...... make yourself happy. Makes no difference to me cause, ya see, I really don't give a rat's ass.