Somewhere on the SM site there is a feature comparison list that shows the differences between the standard and pro versions. It should be on the main Poser product page but I'm not having luck finding it. If I do I'll post the link. The fitting room is one of them, along with various content creation features that the standard version doesn't have access to. Personally I'd suggest getting the pro version even if you don't think you will use all the features right now, you will probably want the ability to adapt some of your older content to the newer figures at some point. But if you're just coming back to Poser maybe the standard version is your best bet until you get up to speed with all the changes. If you're familiar with 9 or 10, then there's not a whole lot of apparent changes but if you're coming from something older like 8 or 7, then it will definitely be a new environment to get used to.

And yes there is a new male figure coming. ;-)

ETA: Here's the info on Collada in Poser Pro: https://my.smithmicro.com/poser-collada.html

It's in reference to Poser 10 vs Poser 2014 (pro) but the same should apply to Poser 11/11 Pro.