You should ask your kids what they like. Some kids like to dive for coins and stuff in the deep end and others may be quite happy with five to six feet deep. My daughter likes a deep end so we built one. It is true that the deeper you go the more of a slant the pool generally will have and that does take away from the shallow end. However if you are not interested in making the pool comply with requirements for diving you may be able to have a cliff where the water goes from five feet to eight feet in one spot. I'm not sure what code requires - you're may only be permitted to drop one foot every three feet of slope.