a sequence is just a loop of midi notes, there is no difference really.
I use both loops of my own audio and midi triggered vsti synths.
Makes no odds.
I love ableton as it is so easy for me to manage what I am doing.
Most hardware PA`s these days sound very dated and slow to react to the crowd being presequenced sets that can`t be deviated from very quickly or easily.
With ableton I can play my live pa with the same reaction speed of a DJ, and if people aren`t digging the tune I am playing I can very quickly move on to another tune to pick up the pace.
It`s so easy to edit midi on the fly, copy, merge it, change it, re-assign controllers, change the groove of an audio loop etc
Plus as you mentioned I can apply processing to keep my sound more standardised regardless of what system I play on.