My experience of IPL practitioners has been limited, but I'd have to agree with lagirl.
While "testing" a number of clinics, I tried one that used IPL. At first glance the lady seemed knowledgeable... she pulled out books of graphs to show how the IPL targeted hair, and it all sounded very scientific.
Then she told me that IPL was ideal for people with darker skin types.
"Really?", I said. "I thought the Nd:YAG was generally accepted to be better."
"Oh no!", she assured me. "You are much less likely to be burnt with IPL."
This was the exact opposite of what I'd read on these forums, but I smiled politely and nodded.
Then I asked her about tanning. Despite having just told me the IPL worked well on darker skin, apparently tanning was an absolute no-no. Oh, and fake tanning was bad too. I could understand this (if the skin was darker, for whatever reason, it would obviously heat up more), but what about applying a fake tan a few weeks AFTER the treatment? Surely, provided it had worn off before the next session, there wouldn't be problem? No, she insisted, that would still be a problem.
It was at this point I decided she didn't have a clue what she was talking about.