I play live exclusively with a laptop & usb audio interface. Never had a problem whatsoever. I too have different speaker setups depending on the size of the hall I'm playing in. Most laptops can do the job without problems nowadays as long as you have a decent interface (I use this - http://www.focusrite.com/products/audio_interfaces/scarlett_8i6/ )
I can go down to 3ms latency with no problems but for extra security I use 7ms. If its a gig where there is already a PA then all I need is a small suitcase (with wheels on I hasten to add) which contains all cables, laptop, laptop stand, headset microphone etc. Then my guitar & I'm away. I travel to a lot of gigs on train so obviously the laptop suits me better than a rack

Last edited by bupper; 04/21/12 02:42 AM.