Flushing is vital, and when you look at the difference in yield between those who go 1 week vs 2, the 1 week flush will produce a heavier yield by a matter of grams, not ounces. BUT, you will find that the plant flushed @ 2 weeks will have a much better flavor as it will allow ample time for the plant to autumn off it's fan leaves and feed on it's stored nutes & sugars.
CHLOROPHYLL is the main chemical in fresh cannabis that creates harsh flavors, and if too concentrated, can create that unwanted "hay like" flavor & aroma. By allowing that extra time for your plant to feed on itself and yellow, you are greatly reducing the chloro levels and will enjoy your smoke much more!
If you ask me, I say sacrifice the few grams and go for two weeks, the quality & flavor will be well worth it!
*** Don't forget to run LOTS of water through your soil, and towards the end, gather some runoff and test it with your PPM/PH/EC meter. That is a great way of knowing when your soil is truely clear of anything containing nutrient value ***