using midi to sync 24 with my 303's

[dirty_bass]

for your ableton problem, just go into the midi delay section in preferences and adjust until your 303 is back in time.

sometimes analog sequencing can be a bit more "human", mainly because it drifts in interesting ways, so I wouldn`t say it`s tighter, but it can be preferable sometimes.
I do hate midi though, time for a new protocol I think.