While I didn't like all of it by any means, and it made many changes I considered unnecessary I did still like 1.6 a good bit in large part do to DoD and OCT. I was very unhappy for the first month or so till thy started getting basic/major things fixed though... that was one insanely buggy patch. Once fixed while not the best FF had ever been, not the worst either imo, though it did take some getting used to.
1.0 was the start of the major changes and decline of the game that removed it's long term stick for players, 1.7 was the final killer. I recall on steam charts 1.6 did still produce a nice surge in players, then they dropped off pre 1.7, it came out and you got this tiny little brief spike before it just flat lined.