Mira has been around longer than any of them and was the original top-of-the-line DOS image processing package for scientific images for several years. It had many advanced functions for science applications, photometry, image stacking, calibration and data analysis utilities and was also very expensive. Then a few years back the first windows version was released and I bought it and did some beta testing for Mike Newberry, founder, principle and main programmer for Axiom Research.
It's still going strong with a new release recently (see
www.mirametrics.com) and personally I think it still has the absolute best image registration routines that I've seen. it just has never gotten it wrong in the 5 years or so that I've been using it and it is very well written. I still don't know how it can animate 100 full-size ST10 images at 40fps on my machine which only has enough memory for about 40 images.