I'm very happy with the way the game plays without a right stick. Target lock is amazing. The only time I use the touch camera controls is when I'm dealing with small, non-targetable monsters or dealing with that one really huge boring monster where you don't have a lot of space to maneuver around him and the target points you at the center of his body.
There are a lot of instances where the lock on is better than a right stick.
Underwater, when the monster ends up above or below and moves past vertical. You'd waste lots of time turning to face them manually where I just tap L and then push up and X to charge in at them.
Agnaktor is good too. While monster's are underground, the target icon greys and you can't use the lock, but it's pretty easy to see when it becomes available again and quickly turn to where he popped up. In Tri, I had many situations where I found out where he ended up just in time to eat a laser to the face.
With the touch screen d-pad, I wish there was an option to just make the touchscreen work like a trackpad. Then it'd be flawless.