Hi:
I gig with the Tyros2 and the Korg PA800, my backup is a new PSR S900.
Why?, because as a former organist I am so used to have available 2 or more keyboards while performing.
As example, I use the arranger in the T2 and have diferent sounds in the PA800 besides the sound on the RH in the T2, for the next song I may use a style in the PA800 and just sounds in the T2 besides the 800.

Also is a great source if you have to play more songs let's say foxtrot, I have a GREAT selection, not only in the T2 also in the PA800. Makes it more FUN !!for me and my audience, if someone requested a song that I played in the previous set, I may play it in the other board, so, it may be the same song, but it will not sound the same.