Speaking as an Anglican who is familiar with the Catholic Church and the Orthodox Churches, there are quite a few more differences in theology beyond ecclesiastical structure than initially present themselves between the three, even among conservatives. That is part of the reason why most conservative Episcopalians aren't quick to jump ship and join one of those bodies.
The Anglican Missions movement seems to be filling the vacuum for Conservative Episcopals where they don't need to jump ship, they are finding their traditional roots and values in their own churches again.