If you are planning on shooting over 400 yards the difference becomes pretty substantial. I missed an antelope a couple years ago in Wyoming at 830 yards due to not adding elevation into my shooting solution. I am pretty accurate at that range normally and was very surprised when he ran off. It will also effect the wind drift calculation part of the solution.
Turned out I was able to crawl up to 342 yards and kill him. He had a very nice pierced ear from my first shot.