Straightforward - Glad you like them. I use poly modelling only for pretty much anything i do these days, I just find it by far the most effective and simplest way to achieve what I want. So no, there are no splines, patches or nurbs used in these heads. I tend to start with a single quad and extrude out the profile (often following a photo for reference) and go from there.
You are right about the faces looking similar. As other people have noted, I am using one base model from which i am creating all the characters. This has the obvious benefit of being quicker but it does mean that no one model will be entirely unique. The female head has gone though some serious ammendment phases already and if I have time i’ll go back to one of the male characters and make the model truely unique.
As for hair, this is my achillies heal
My characters are almost always bald as I don’t get on well with Shag:hair and lack the patients to make quality polygon based hair. I reckon i’ll have to for the female though so i’ll let you know how I get on, but the basis of it will be wavy polys with an alhpa’d hair texture applied I imagine.
Xero - Your input is always appreciated and it looks like you are right about the nose, i’ll be fixing that next time I go back to her. As for the lips, i’m quite happy with them so will probably leave it at that and I really do need to move on. Although now you mention it they do look a bit pursed… 
Kragh - Hello again, glad to hear your sticking with the competition - why have two dimensions when you could have three! 
Her skin is pretty flawless now and I guess that comes down to preference. As i’m going for the movie poster feel for the final thing I think she should be made up to perfection like you’d expect from a hollywood actress - particularly an air brushed one. The eyes I agree with, I think I upped their self illumination and the added brightness has probably knocked some of the depth out of them. I’ll address that.
As for Kane, he does look a bit cross eyed (that what you meant?) which I hadn’t noticed until you pointed it out and yeah, his head could probably be smaller (I already made it smaller once, he looked like a dwarf this morning :)) The lats (wing muscles) are very small, however I have done this semi-intentionally (honest) as i’ll be lowering his arms and therefore occluding them from the final shot. I guess that they’ll get in the way if I put them in.
The textures for the torso really are nothing special - just some sploges of colour in Photoshop that are painted to fit the UVW map. I haven’t really gone to town as the torso will be fading out into the rest of the scene.
Crusty_Butt - Hi Brett, the head will be getting a smaller and i’ll try raising it a bit. And following on from my reply to Kragh, the lats are small but I don’t think i’ll worry too much about changing them as they won’t be visible on the posed character. Although having said that now you’ve planted this in my head i’ll have to go and sort it.
Cheers to everyone who’s taken the time to comment on my work, your critique is invaluable and I am making a point this time around to address every issue raised so keep 'em coming.
Thanks guys,
Dave.