Grading in traditional climbing

Grading is often the source of much controversy especially with first ascents. Once a route has become established and repeated a few times the grade becomes more secure. However if all the climbers who repeated the route were between 5'7 and 5'10 and you are either under 5'0 or over 6'3 the grade could be very different. As a result it is best the use grades as a guideline and not stick to them religiously.