Well, RNG...
A friend wanted a spring on F4. He did it 10 times in a row, and did not see even one. At the same time, my group dropped 6 springs in 4 runs.
RNG...
For me this is definitely better than before. But I can see getting the items you want outside of a static group can be tricky (people in PF will leave once they got their items, and you have to fight against potentially 7 other people in DF).
I think a system a la 3.0 EX primals would have been better.