I have to agree when i did my fATPL's i was still working full time and i can assue you doing that much work in 12 Months wasnt easy.
And before you say compared to a real degree etc.. I also hold a BEng (Hons) degree in Microelectonics and Computing and again i can assure you that wasnt easy either.
I would have to say the ATPL was just as hard because of the amount of information you have to learn, not because of its hardness.
Plus it was more expensive than my Degree.
But thats my personaly perspective on the subject