I wouldn't be indifferent. If I had to choose between being wireheaded and being antiwireheaded, I would choose the former. I don't simply assign utility = 0 to simple pleasure or pain. I just don't think that wireheading is the most fun we could be having. If you asked someone on their deathbed what the best experiences of their life were, they probably wouldn't talk about sex or heroin (yes, this might be an ineffectual status grab or selectively committing only certain types of fun to memory, but I doubt it).