I never use direct monitoring because I like having the PT effects running during my recording sessions. The latency isn't really that bad, it's just part of the process. Plus, if I were to use direct monitoring, I lose out on any panning I've done in PT to see how other tracks I'm recording are sitting with everything else. You also miss out on the ability to tell if a track is record enabled. I actually think that direct monitoring is a hindrance. I hired an engineer 3 years ago who used direct monitoring and because of this, wasn't able to pick out some major problems with what was going into pro tools until it was too late. Let's just say it was a $4000 lesson learned.
Kevin