The number of satellites is not that important, 6 in the right configuration might work better than 15 packed together.
And there is no way to say (besides visual red/white) indication how good your signal is (there are some apps and tools but ....). In some parts of the world where satellites are "spread" better fewer satellites yield better results, in others the same number of satellites will give us less accuracy. Also in some areas of the world GPS accuracy is intentionally crippled, for whatever reason.
wiki.openstreetmap.org