Pood, I usually use phrase and exact match keywords. I've noticed that with Adwords when I use broad match, I don't really get much more data from Google in terms of what keyphrases triggered my ads. If I run a report, I usually get a bunch of fields that say "other related search" or something like that. That doesn't really tell me much. On top of that, I have to guess, if the searcher was in fact using a phrase that was relevant to my ad.
If you stay on top of your negative keywords, you can use phrase and exact match to drive more targeted traffic to your site. If you have the money to blow on testing, then keep testing with broad match.