I prefer to use Live 4.0 as my main audio sequencer. I know Live is not intended to replace Cubase, Pro Tools, and the like, but for me, it gets the job done. There is, however, one feature that most all audio sequencers have that is missing from Live- a time display. You know, the song (Arrangement) starts at beat 1.1.1, which would be 00:00:00 in linear time, then the minutes and seconds increase as the song progresses.
One obvious complication of this is the fact that Live is capable of tempo automation, but I think the way around this is some kind of "dynamic" time calculation function within Live's engine- For example, if you enabled the "Time" display, Live would calculate the elapsed time in the arrangement view in REAL TIME from the start of the arrangement. That way, regardless of what tempo you're using, etc, you could always jump to a point in the song based on time instead of measures. This feature could also be disabled (unchecked) to conserve CPU power.
This feature would be invaluable to anyone with time-based needs, ie, scoring. I recently did a project in Live for a coreographed trapeze performance for my friend LPP, and had to constantly monitor the length of the song as I made edits. The only way I knew to do this was to render the song periodically and check the overall length of the rendered file, which was quite time-consuming, as I did MANY edits a day over the course of a week.
I refuse to buy Pro Tools!
Peace, GFEA