Is there really good distortion correction software?

I see you have ruled out PTlens which has dual distortion controls. I found it good but each to his own.

If these are fixed focal length lenses, here's another approach:-

Carefully make a target image preferably like graph paper with a regular rectilinear patterns across it all but bigger so the focus isn't set close.

Open it in your CS5 and don't crop the image. Create a new layer (for safely re-working if needed). Record a new 'Action'; use your correction techniques including 'Warp' to get the rectangles correct. Save the action and you can use that for any unaltered, full frame, uncropped image from that same lens before normal post processing.

Have used this technique before, successfully.

Just a suggestion.

Cheers, Tony.