Why did you change from using a head to a power amp/preamp set-up...or why did you change from using a power amp/preamp setup tp using a integrated head? I'm looking to build a new rig for giging. Medium size venues, playing funk, blues...etc Looking for others to share their experiences with this issue. I used to use a rack systems years ago (many) and thought it was heavy and cumbersone. Things have come along ways over the years. A power amp/preamp rig using a QSC PLX or Stewart World can come in a three rack space bag weighing 22-30 lbs. Integrated heads have come along way as well. Opinions sought!