Honestly, it depends on who makes the recording. Usually I like to just read them to give the charachter a voice that I think fits them. Like Penny for instance, in my mind her voice tends to be that of someone in their early twenties, chipper and happy with the little remnant of teenage attitude carrying through at times while being able to sound low and sultry on occasion. Kinda like a weird balance between soft and hyperactive. I dont know how others think the voice of Penny would sound but I enjoy the way I think it fits. If this babble makes sense I hope it helps.

Summary of rant: Personally I think the voices in my head are better than other people recording for an audiobook version of stories here or on fetish sites.

I'd definitely say it depends on who's doing the talking. All of the stories I write and release here work better with different voices reading.

After being on the internet for so long, nothing surprises me anymore.

But to answer your question, It would be interesting. I've been a part of the MLP FIM community for years. There are countless people who turn smut fics into audio stories. While I haven't written any smut fics for MLP, I've had 3 of my fics turned into audiobooks.