where are you in the world Steven?
Many northern/ southern places (globally I mean) don't get bright enough sunlight for sunny 16 to work. I think we had a recent thread on this, but at the risk of repeating myself, I find sunny 16 always underexposes, so I use the sunny 11 rule instead.
Also, urban locations will have added sunlight filters with pollution etc. so again, the f16 rule will underexpose .
Also, sunny 16 doesn't really cater for subject brightness range differences, which differ with conditions, shade/ vs bright sun and so on. A meter reading will read all values in its scope and provide the average of them, which sometimes is not best exposure settings to make.
As LD says, why not try both and see which you are most happy with.