I love it! I make loads of stuff with it and use them in Poser and Vue. I'd say it's fairly easy to learn - and I have no real-life sewing skills whatsoever. People who actually know how patterns work can do some amazing things with it.

You can use it to make objects that can be draped in the Poser cloth room. I've never done that because I started using MD before using Poser, so I drape everything inside MD (works nice and fast!) and then export the draped object and import to Vue or Poser.

Rosemaryr does amazing MD work - you can see it in her gallery here:

http://www.renderosity.com/mod/gallery/browse.php?username=Rosemaryr

There's usually a month's free trial so you can download it and give it a go.