I did mine roughly a year ago and it had a few zig-zags in the route to ensure that I covered the correct distance. The route was chosen by my instructor and the two aerodromes were ones I had been to previously with him. I flew the whole trip entirely to plan and with no significant hiccups; however a couple of days later anther student at my flying club flew a virtually identical route and arrived back with one whole tach hour more than me. I was there when this came up and he began to quiz me in front of everyone about this, more or less asking me directly if I had taken any short cuts (which I hadn't). Several weeks later, we had our skills tests booked within a few days of each other. Mine went okay and I passed; he failed his on his nav as he got lost on numerous occasions and spent most of the time orbiting trying to figure out where he was.