we just took our son out of a school like you describe ... He spent his days being stressed - all the time ... I think weather or not your child excelled n such an environment doesn't depend on being gifted or not but on the personality. I you already have a child that is prone to perfectionism or a low self esteem - this might be a BAD fit. It is exhausting to " keep up" with highly driven peers ( or rathe their parents). Our school had a large percentage of " Tiger parents" - lots of extra tutoring even for obviously " high" kids. Our son did well academically but lost all passion for learning and developed an intense dislike for competitions of all kinds.
There is certainly no harm in trying though ... some kids do well with some pressure - my daughter loves the same school I took my son out of and doesn't even seem to notice the high expectations.
I learned over the years to go with the flow ... try things out and ... admit when they don't work ... I always have a " contract" with my kids ...: we try for one school year ... we are prepared to give it our best shot ... if it is not working ...we'll change it ...