Montessori has been wonderful for my dd9, who is still there in 4th grade (generally doing 5th and 6th grade work). I have read of cases where it wasn't a good fit for gifted kids--my impression is that may be at schools that are die-hard Montessori (you must progress in exactly this way and you will not be given new lessons until you can show that you have mastered the previous work). My dd's teachers have been pretty flexible. (also--I think her LOG is easier to manage than your child's and she is sort of a typical teacher-pleasing girl). So far for dd3 it seems like the best option for her...I don't think it will be that great when she is the oldest in a class though.