Predators do have huge heads. I used to think the AvP predators had oversized heads but now I'm not so sure - I think it was those old style dreadlocks, that stick out quite a bit in some pics, confusing my eyes. The new dreadlocks hang by themselves, no manipulation needed. As a former sceptic myself I now think the proportions are fine on the predator figures.
The aliens aren't quite so good. You may have had the Aliens warrior in mind when you said they look funny - that one was a bit innaccurate in the shape of the head (yet they got it right with the BD P2 preds Alien skull trophy) and seemed even more 'alien' in its body shape than what would have been used in the film. They may have taken a McFarlane-esque interpretation approach rather than completely mimicking the suits. The dog alien is looking to be incorrectly proportioned too, the legs being too thick.
Oh yeah. Wolf was made too skinny. His legs look a bit anorexic. Still love the figure though, the face is fantastic.
Ok lets take the AVP predators as example. Take a look at their feet and hands, something's very wrong there. Clearly either their body is tiny or their head is huge...even without the dreads, same with their wrist blades or the huge ones at the side...they should be much bigger. Well, if HT followed the man in the suit format, their would still be problems, since the preds in AVP were goofy (bloody Anderson)
Bah, this is getting pointless. Either way these r the only up to standard merchandise their is in the market right now. I'm looking forward to see the PI predator and the A1 alien though, I might get them.