Having considered the dangers, here are the advantages that M'Cheyne identifies. These advantages are mainly if you use his plan, but there are some that apply to any plan. I've updated the language and application for some.
(1.) The whole Bible will be read through in an orderly manner in the course of a year. The Old Testament once, the New Testament and Psalms twice. Since "All Scripture is God-breathed" (2 Timothy 3:16) then it's good to read it all!
(2.) Time will not be wasted in choosing what portions to read. Often believers are at a loss to determine what they should read. Here the question will be solved at once in a very simple manner.
(3.) If we were all to use McCheyne's plan, then it would mean we could discuss it with each other when we meet up, McCheyne wrote "Friends, also, when they meet, will have a subject for profitable conversation in the portions read that day. The meaning of difficult passages may be inquired from the more judicious and ripe Christians, and the fragrance of simpler Scriptures spread abroad."
(4.)The sweet bond of Christian love and unity will be strengthened. We shall be often led to think of those dear brothers and sisters in the Lord, here and elsewhere, who agree to join with us in reading those portions. We shall oftener be led to agree on earth, touching something we
shall ask of God. We shall pray over the same promises, mourn over the same confessions, praise God in the same songs, and be nourished by the same words of eternal life.
What other advantages are there?