I had the opportunity, due to zoning changes, to have my child attend a 2/3 combo-class environment. It sounded ok to me, but I knew already that my child was able to perform above grade average in reading and math. My 2nd grade child was and is at a 4rth grade reading level, math- I don't know yet...we are waiting for the "gifted" test and results at her current school. But if she should not qualify for the gifted program, I might consider the alternative- combo enrollment. As my child is a higher-end performer in 2nd Grade she might qualify at least (if not gifted) for combo 3/4th grade.