Akira - I understand the new photomerge really has been improved a lot - do you find that to be true?
Elsa, the photomerge I used for the first time was that in Photoshop Element 11 which I felt pretty handy. Then the one in CC2014 turned out to be a vast improvement over the PSE11 version in terms of the accuracy. I was also very impressed how Photomerge can stitch random patterns like the surface of the running rever and the clouds smoothly. The on in CC2015 is the further refinement albeit not dramatically improved. It stitches handheld images really well. I cannot find any glitch in the first and the third iamges.
That said, it is NOT totally glitch-free. Sometimes it fails to stitch the power lines commonly seen in my images smoothly. Nothing is perfect. In the second image, there ARE only very minor glitces shown below (100% crops).
Needless to say, the proper alignment of the leveling and the entrance pupil on a pano head helps.