One other thing to be aware of is that now both the Pro and Standard version of poser 11 use Gamma Correction. This will cause the images to look different between 10 and 11 Standard versions. Having used the Pro version for several years it becomes a mute point, but if you are not prepared it can throw you off. It could also be why some say that Firefly is different.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13