Welcome back!

Since you mention DAZ Studio, the biggest change is that (as others have mentioned) with the latest versions of both programs (Poser 9/Pro2012 & DS4) there has been a divergence. I’ll leave out the Armageddon like brawl that erupted over that ÷) Others can elaborate on the technical details. Suffice it to say that going forward, it seems likely that there may be less content that can easily be used in both programs. If getting a lot of the latest greatest stuff is important to you then the choice may be significant. I think it’s still too early to say which one will be more supported in terms of the latest features. People have strong opinions one way or the other.

Coming back after a long break may give you the luxury of making a more objective choice. Download the free DS4 and try it and do the same with the Poser demo – see if one or the other suits you more. I guess the new Poser sale limits the time frame if you want to get it at a deep discount. Ignoring features and content, one plus in Poser’s favor is that the forums here may provide a greater of information and assistance simply because it’s been around longer and developed a number of very helpful and (occasionally over) enthusiastic users.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken