There are issues with certain design choices - they take much longer to sim. They are also relatively easy to avoid or to correct. See FAQ on www.e-frontier.com

"Q: Are there known problems with the software?
A: Yes and no. While the software performs well while in Virtual Fashion, some design decisions may affect how the garments simulate in Poser. These are mainly narrow bands and cuts that create “jaggy” polygons, and some collision with stretched garments that may collide with other garments or the skin of the model. Both cases, as well as workarounds are described in the VF Basic PE (Poser Edition) User Reference Guide Poser section starting on page 45.