Just a thought.  I love IDL, I really do, it looks beautiful, makes me all gooey inside to KNOW that with Poser, I can summon this stuff at the click of a few buttons (I've been into CG since about 1981, so I still get a kick out just what Poser can do), knowing, just knowing, that IDL-based pictures are better than non-IDL based pictures. 

Then - I try and point out the differences to my wife, who is pretty Switched On.  Her eyes glaze over when I point out the subtle, but still discernible (and to my mind, vital) differences between IDL and non-IDL Poser renders.  She asks the not unreasonable question "so that one with the hair took 9 hours with IDL, but only 30 minutes without it - I don't see it makes that much difference, surely it's more about the composition, the original idea etc".  I have to admit, she has a point.  IDL renders are indeed beautiful and creamy and I love them.  But are they worth it?  Then I look at all the Poser renders I have ever sold, and ask myself, a) which of them have IDL and 2) which of the art/comissioning editors gave a flying fig whether or not I used IDL?

The answer, sadly, is none of them.  It is my belief that no-one really REALLY notices IDL except our fellow Poserers when we tweak THIS to make THAT etc. 

Just my opinion, backed up by a few facts based on my own Poser useage since 1996 or 97, I forget which.  Other folks might have a different experience.

To answer the OP; IDL and hair - forget it, by and large, it's just not worth it, is my honest belief.

My self-build system - Vista 64 on a Kingston 240GB SSD, Asus P5Q Pro MB, Quad 6600 CPU, 8 Gb Geil Black Dragon Ram, CoolerMaster HAF932 full tower chassis, EVGA Geforce GTX 750Ti Superclocked 2 Gb, Coolermaster V8 CPU aircooler, Enermax 600W Modular PSU, 240Gb SSD, 2Tb HDD storage, 28" LCD monitor, and more red LEDs than a grown man really needs.....I built it in 2008 and can't afford a new one, yet.....!

My Software - Poser Pro 2012, Photoshop, Bryce 6 and Borderlands......"Catch a  r--i---d-----e-----!"