While I personally am not into most futa, I disagree.
Futa on female is the midle ground between straight porn and yuri porn: it is yuri, but they have a dick. Futa on futa is the same idea, but they can alternate.
Male on futa is... not for me, really. Kinda the same as male on trap for me, but futas have a vagina.
Better used in3+somes, though, since it can be with a girl (or another futa) while being fucked. Or, you know, dp on the extra.
Futa on male is kinda a mix of gay and femdom for me, though. So... pass, no offense to those into it.