|Belt and Suspenders
Hopefully I won't spend the whole entire time staring down at my GPS; missing everything around me. I like the cues and computer because all you have to do is look down once for the cue; and then again when you are near the turn(or earlier to work out when you'll turn) and then at the turn. After days of riding you can generally work out your speed w/out looking at the computer and just time your glaces at the cue before you get to the turn. I'm not really sure you can program the GPS to beep at each turn for these off road/trail situations.
Cue or GPS; I'm excited about getting out there; it's been too long.