I use mesh warp a lot when I'm working. It's great because I can start with a 

basic corner pin and add more and more control.

Working for Walt Disney Imagineering, I've use it on Many rides (over 50 rides and attractions)

including the new "Mystic Manor" at Hong Kong Disneyland

But it is also a pain in the tokhes sometimes.

Below is a list of added features that I think would make it a much stronger plug-in.

• Arrow nudge selected points (Shift Key depressed 10x)

• Use layer mask as warp edge

• Lasso Selection of points

• Live update when moving a spline(GPU?)

• Don't deselect when using the hand tool to navigating in comp window

• Option Command click on a point to Lose or create a spline (Like with mask points)

•  Allow user to add a Row or Column where needed (i.e. click on an edge and where you click is a new line)

• Shift Hold to force move to right angles and Shift option to for 45° increments 

• Select whole row or column by option click on a line, Add more wIth shift key

• A "reset selected points only" Option

• When adding lines or columns to a mesh Don't break splines (or just implement • 6)

• Add a Photoshop "Free Transform" type selection manipulator

• Allow more the 31 lines

• a Pref window to turn on or off features (if not in the control window)

and yes I've submitted all these to Adobe wish list 

Thanks

Chris