I think that 3 under,or split, doesn't make a whole lot of differrence.
Probably the way we were taught, and what ever feels comfortable and gives the desired results.
I shoot 3 under, and have tried split, but feel the most comfortable and accurate with the 3 under.
Which ever one you choose, give them a fair assesment, and follow that venue that works the best for you.
No one way is best for all of us.