Personally, I find DAZ a lot more intuitive than Poser, as it's closer to what one expects in a 3D app. Also Poser has to be one of the slowest 3D applications I've ever seen. I have a fast PC (core2 duo 2.4GHz, 2GB RAM, GF7950GT), but it's really testing my patience.
Poser has more features than DAZ and is better for some tasks, but I'd rather do everything in DAZ if possible. DAZ 's renderer isn't going to be enough if you want to render complex scenes directly in it, though.
But anyway, both share many of the same problems. Both are really poor at posing characters. Yes, that's what they are made for but still compared to how easy it is to pose a well rigged character in most general 3D applications, both DAZ and Poser seem incredibly inadequate for the task.
So in the end if you want to be able to use the huge amount of content commercially available (and that's what it's all about isn't it?), there is no choice but to choose the lesser evil.