I play with imac intel core 2 duo.
Time ago i use ibook , but the big screen on imac, its perfect, the mac work asbolutly cool you not have thing about temperature, specially on that clubs with high amount of people and super hot temperature or summer places : )
For make portable i use modified SKB
http://media.zzounds.com/media/brand,zz ... e48835.jpg
I remove the aluminium mixer support of this skb , and make special foam, for move and have super ATA protection for travels.
Imac, + fast trak pro + my 15" inch touch screen, for my monotouchlive system, all inside of the skb : ) and suepr protected.
Its true, macbook / pro its very little and portable, i know, but with imac you have this pros:
1: Work very cool
2: Imac core 2 duo 1.8 ghz with gma graphics, its not epxensive, and faster
3: You have 7200 rpm HD and 160gb !
4: Big 17 screen
5: More USB ports if you need more : )
6: On clubs its very easy some stupid or drunk guy can splash beer or other drink over you computer.
In this case on macbook or mackbook pro, little drops over the keyboard or mouse pad, can transfer to main board and your macbook /pro just die.
This happen to me time ago, in accident and one g4ibook die, and too many times happen with no destructive situation but this happen, specially on clubs where you play very close of the people dancing.
On imac the only way you can demaged its if you put all your bear on the screen and splash a lot of drink over screen.
Its the only way, imac have wonderfull constructions, aditional to that y not use keyboard for play live, so i not use keyboard, just mouse and midi controller.
Anyway if your keyboard its demaged for some drink, just can cheap remplace.
The bad point: well!! not its a notebook, so no its a super portable, but is the best desktop portable solution.
For me its the best !!.......
Sorry for my english, my native language its spanish guys !!
Cya!