Subjective...Different people's skin grows and changes differently. In fact, very few are in any way alike.The best bet is to get one where you'd really like it to be and have it touched up every few years to keep the color vibrant and strong. As you get older (to the point that the skin is sagging and what-not) it's likely you won't be worried about it as much by then anyway
Get what makes you happy where you want it.. otherwise. What's the point?