i am one of those artists who likes to see for himself 'if it works'. i use both daz and p5. the daz program is set up to use poser items up to i believe up to p6 maybe poser 7.2 things it cannot do yet are dynamic and read material files native to poser which i figure it probably will be added soon.
 the majority of my runtime is full of free items with an ever growing spackling of items i've bought both here and at daz. i can honestly say for  the most part everything has worked even with some tweaking on my part.
 imo the vendors i know and /or bought from give ample warning in their readme's if something will work in in ds or at least say they haven't tested it in ds.it in no way means it won't. i think if every vendor could give at least a heads up like that it'd be a big help for all involved.