I'm a pro shooter and I've been using PTGui for at least a couple of years now. I'm very surprised that there are no reviews of it here, so I am going to pipe in. I love this app! I have seen it mature with many updates. This is a very powerful app with a huge amount of control. The interface is somewhat daunting but worth the effort. Originally, the app was a Graphical User Interface that ran the Panorama Tools engine (hence, the name PTGui) written by professor Helmut Dersch. It has since gained its own engine but can still use professor Dersch's engine.
To be fair, the stitching engine within Photoshop has also matured into a great tool and for many people will be entirely satisfactory without purchasing a 3rd party app such as PTGui. Photoshop's stitching interface works completely automatically and usually does a very good job. However, on the occasion when it doesn't work well, PTGui can get it done. PTGui is also my choice when creating a 180 or 360 degree VR.
Id' write more but I've got to get back to work and make some money.