if your child is a gifted child in certain aspects, SFA's program is better to suit as TSL is not that vigorous in academic development in the first few years program, but good at overall and gradual development. Some gifted child may feel boring at some of the curriculum as it may be less challenging and interesting for some kids, even with the enhanced class kids.
All depends on your child's development stage and your parenting styles...
Not attacking TSL, just stating my opinion and some facts from the kids I know and some curriculums I know from TSL and SFA..and of course some parents I know from both schools.
I would choose TSL. I wish to let my kids learn in a more interactive environment, which I believe would be beneficial to kids' long term development.
No doubt both are good schools (their only drawback is the lack of secondary school connections). Or else, they are both excellent choices!
Depends on parents' expectation and time allowed to supervising kids' academic work. SFA's acadmic achievement may be better. But be prepared to spend more time on supervision.