On short trips, errors in route-finding don't make that much difference. Usually, you have plenty of time, energy and daylight to compensate for wasted time accrued through taking an inefficient route. But, on longer trips and during the winter months when days are shorter, and trail-breaking frequently heavy, efficient route-finding can make the difference between reaching your objective and getting home during the daylight hours, failing to reach your objective and having a frustrating day, or even finding yourself benighted.
I've been up what Doug and I refer to as Qua Peak (map 82F/06, GR926730, NAD83) four times now. It's a stunning trip involving a bit of everything, two long descents (not counting descending the ski hill at the end of the day), one south facing and one north facing, some step-kicking, and frequently, cornice cutting, and lots of travel and trail-breaking. Qua Peak is a long day for most people, involving between 1450 and 1700 metres of elevation gain (depending on your exact route) and about 15 km of travel. And, if you climb Qua Peak in December or January, daylight hours are relatively short and you must move expediently.
The last two times I climbed Qua Peak were in the month of January; once in 2010 and, most recently in 2011. These last two trips are clearest in my mind and provide a good comparison of the benefits of efficient route-finding. The best (in my opinion) route up Qua Peak is shown on the map below, with the most expedient exit from Qua Peak also shown (the descent via West Ymir - as the slackcountry tourers call it is not shown, but implied). As you can see, rather than following the head of Qua Creek up into the basin below Qua Peak, the most efficient route actually travels further east towards North Qua (GR930742) before climbing gradually around the steep NW shoulder of Qua Peak to gain the upper basin.
Qua Peak and routes
While this route seems much less direct than following the head of Qua Creek up, it is in practice much more efficient - that is, it uses much less energy to build and follow the up-track, than following Qua Creek up. Good map readers will note that the contours are not only closer around Qua Creek but have a deep V indicating the creek itself is in a deep gully. In 2010, when we climbed Qua Peak, owing to some now long forgotten route finding error, we switchbacked up close to Qua Creek to gain the upper basin. Track setting was very difficult and involved countless steep kick-turns. Breaking the trail was a real energy sap, and even following the trail was tiring. In 2011, with a small tight-knit party, we were much more careful with our route-finding and followed the route farther to the east, and easily broke trail to the upper basin using much less time and energy.
You'll note that even though you are in timbered terrain in the bottom of Qua Creek there are handrails and checkpoints that can be used for route-finding. Not visible on the NTS 1:50,000 map, but visible on Google Earth and when you are actually on the route, a large slide path descends from the east side of the NW spur ridge of Qua Peak and should be your indicator that it is time to begin switchbacking up. If you are concerned about stability, you can skin up trees on either side of the slide-path, but Qua Peak is probably not a good choice for periods of poor stability anyway. The sharp NW spur ridge is also a good handrail, but it is not readily visible until you have gained elevation.
On the return journey, you'll notice that contouring generally west at about 1800 metres around the southwest ridge of Ymir Mountain avoids difficult track-setting higher up the southwest ridge (and avalanche terrain) and leads expediently to the gentle valley that leads to the west Ymir col. If stability is good, descending from West Ymir is quick and easy (but often chewed to rat-shit).
You don't need a GPS for this route as there are ample handrails, checkpoints and other navigation cues that you are on the right route, but an altimeter is handy, and, of course, a map, indispensable.