Hi John
I have mused the same question many times myself. As Colin has so aptly put it,and you already know,there are advantages in using the sequencer. Having said that,I have found that some people think you are running a karaoke if it is overused. If you include too many tracks,e.g.,it is quite obvious you are not playing it all. Then the question becomes, are you playing anything?
On the otherhand,APC is partially the same thing.I use a laptop for midi's,which displays the score and/or lyrics,and it works very well for me as I read and can't remember all lyrics. Is that the best way? Probably not. The ideal way IMO,is to know all material cold and try to do what you do.

Some say that the customers today expect a fuller rendition afforded by sequences. If you play as much as you can by yourself,and delete all else,and you put energy into your playing,then I think you can use sequences to some degree with your regular playing. I think the venue also dictates to some degree. If I am doing a singalong at a club,e.g.,I would want the flexibility of the keyboard.
I am cutting down on sequences only for my own pride. The combination of sequences and your own talent,however,produces a better sounding product in some cases,however.

I am still not sure what the balance point is.

Bernie