Hi,
first up, I've never " Performed ", with a band, midifiles or an arranger.
As an outsider looking in, what difference does it really make what the backing is, as long as you're doing your part.

I remember when midifiles first came out
(late 80's , I think), I was paying $30 per midifile. I had very few. haahaa
I was happy when I bought my first keyboard, I had backing.
Eventually midifiles, as the hobbyist market grew, got way cheaper. A lot of them wouldn't have been suited for the pro market, but for me as a hobbyist, they were ok, I was able to play along on my piano. (Personally, I found playing along with piano, more difficult than playing the arranger.)

One disadvantage I would imagine in using a midifile, versus keyboard , is that the performance is set, unless you have some sort of function, to be able to extend the performance if required.
On my Korg , I sort of found a way around it by cutting a midifile into sections and triggering them in style play mode.

By the sounds of things, each of the methods, live band backing, midifiles, arranger playing , has it's pro's & cons.
Main thing is, you're doing what works for you, and you're out there performing. Congratulations.

best wishes
Rikki



[This message has been edited by rikkisbears (edited 01-03-2011).]