Since the ES complex would be in a "energy trough," the activation energy for the transition state would be quite high.
What is enzyme?
Tight enzyme substrate binding will lower the reaction's forward rate constant.
A forward reaction's activation energy will increase when an enzyme's affinity for its substrate is high.
Because the enzyme-substrate complex will be located in a deep energy well, it will be more stable.
In contrast to the situation where the substrate-enzyme binding is weaker, a tight binding of the substrate to the enzyme will alter the amounts of free substrate and free enzyme.
This little modification won't have much of an impact on the reaction kinetics because the substrate concentration is often higher than the enzyme concentration.
It is unlikely that tight binding would result in the active site being altered.
Since the enzyme is significantly bigger than the substrate, it is unlikely that it will change shape.