When I took a laptop on tour; I put it in a rear side pannier, flat against the inside [against the rack], and padded out the rest of the bag with soft stuff to protect it. No problems with this; except that it was not easy to access the laptop, except at the end of the day. This however probably saved the laptop from being flung off a mountainside. Laptops don't seem heavy but after a few miles of up-hill, into the wind, you will think you can tour without one.
Oh and the 60/40 weight thing. I always carried my lightest stuff at the front and have recently cut down to only have need for rear panniers, but I do see the thinking behind putting more weight on the front and might give it a try.
Last edited by Lou Skannon; 10-18-15 at 08:10 PM.
Reason: extra thoughts