I think V4.1 is a definite improvement over V4! a number of issues have been addressed and the new morphs (muscles/creature creator) are fantastic.

Had no trouble installing her whatsoever (in external runtime - copied over the !DAZ folder to Poser 7  "libraries" directory to make sure she works in there as well - you can also simply copy &paste the Poser.exe file into your external runtime), and can still use normal V4 with older projects.

overall, much better than V4 - all from an artistic point of view since I'm not overly technical about Poser.  And maybe i see the difference because I mainly use DAZ|Studio rather than Poser?