Who uses this program? I've messed with it, it's clean as hell. I use FL, but this is really the only "big boy" style DAW that I've come across that I actually feel comfortable using and could possibly replace or be an addition to FL.
http://www.presonus.com/products/SoftwareDetail.aspx?SoftwareId=11
http://www.presonus.com/products/SoftwareDetail.aspx?SoftwareId=11