I am thinking of getting one, talked to someone who is using one the other day and was impressed. Always was interested-not at $1200-$900 looked more appealing, but still expensive. I'm looking at the ver 3.1 for $399. It seems its upgradeable to ver 4. Does anyone know what this costs? Will I be dissappointed not getting ver 4? I do lots of gigs where I need to pull up random charts vs a set list-will this make a difference version wise?