Nope. I'd prefer good and well written conversation over a sex scene any day. The key words here are 'good' and 'well written', though. I.e., the characters need to be characters and the convo needs to be original, not just a plump gearing up to the next fuck.
It would be even better if there was humor and wit in it, but I hardly ever come across a BDSM-story with humor.
To me, there are different kinds of 'slow'. A turn off kind of 'slow' is when there's a lot of unnecessary description. Like when boy and girl enter a room for a sex scene, all heated up and ready to tear their clothes off each other and then I have to read seven paragraphs on how the room is furnished and that its windows are overlooking a well tended, expansive garden with neatly trimmed bushes and a 'Wasserspiel' in the foreground.
That's yawn, skip, next book please.
Slow as in there are four chapters of character development, telling us who that boy and girl are, why they are here entering this room, how she does feel about having her hands tied in a reverse prayer for the first time ever, that's not slow at all. Provided those four chapters manage to bring them actually into life and provided I can relate (to the chick).
No, it's not necessarily a turnoff for me. However, as I have stated above, 'slow' isn't just 'slow'. Unlike the tags 'rape' or 'nc', with which you pretty much now what to expect, 'slow' doesn't tell the reader much.
And yeah, I guess for a lot of persons it would be a turnoff.