Media Manager can do a "create offline" pretty well in FC 5.1.4 except for breaking speed changes. Today I tried the first step of doing my regular HD online with FCP 6. Didn't get past step 1 because Media Manager is again broken and can't trim down the clips.
(create offline with delete unused media selected only) So at least half of the 1000 or so clips in the timeline are still stuck at the original length of the entire dallies clip.
FCP always gets worse and always breaks basic things that were originally fixed years ago.