man.. that can be a controversial question mate.
shooting as you come to anchor, is what is commonly referred to as "snap shooting"- now many shoot this way very effectively - but the concerns might be releasing before reaching full anchor(short drawing)- for me i suffered with inconsistency- some great shots some not so good, i think with me , there were just too many variables that werent being dealt with on the draw.
when i moved over to Rick Welch's shooting technique- with a pronounced full 2 second pause at full draw- it really significantly improved my accuracy- i could settle into the shot better- ensuring proper and CONSISTENT back tension- and allowing my "body" to aim naturally- not just focusing on when i reached anchor alone!!
he teaches you to "trust your bow arm", and i know now, when i second guess my bow arm, my shot will be off in elevation every time.
we're still talking instinctive shooting here. not gap or string walking etc etc