Hi tommowg,
I am currently half way through my ATPLs (8 down) and would have to say that I haven't had too much difficulty with any one thing in particular. As everyone else says, its the volume that really overwhelms you. If you are used to knuckling down with university work/dissertation then you should be quite capable of managing it though ; )
Exactly this!
You'll be fine with the content, it's just the volume that can cause a little stress. Nothing is a specialty, it's just all very broad.