I never have, and I can't imagine that I will in the foreseeable future (considering I'm now in a commited relationship, and have retired from pooning as a result), but I certainly wouldn't rule it out.
I've heard a lot of horror stories on this board, but when you get right down to it, people are people, regardless of how they earn their cash. There's no point in pre-judging anyone based on their job (well, unless it's a really hideous job, like somebody whose job is to plan or carry out genocide or something). Everyone is an individual, and you have to take people on a case-by-case basis.
I can probably say that most SPs are people who I wouldn't date, based purely on personality, but I'm sure there are some gems out there (and based on posts and private messages, I think some of those gems are right here on perb) who I would potentially go out with.
While I can understand that most guys are probably too insecure to go out with a girl who has sex with other guys on a regular basis, I don't necessarily think that would be an issue with me, as long as everything else in the relationship was firing on all cylinders. Of course, I'm saying this from my armchair... If the situation did come up, who knows how well I'd do with it? Maybe I'd end up freaking out and trying to get her to quit. I'd like to think I'm more mature than that, but since I've never been in that situation, I can't tell for sure.