If your instructor is an old glow pilot, he is probably used to highly over powered planes. Nothing wrong with that.

As you noted, the plane will fly as is. As a basic trainer, that is all you need it to do.

You can boost performance in one of two ways. Add power or reduce weght. Go from NiCD or NiXX to Lithium to shed ounces.

Go from brushed to brushless to add power.

You may also find that you have the CG a little too far forward. Try shifting the battery pack 1/4" back and fly again. See if it makes a difference. If it feels better, move back another 1/4". Fly again.

And check to make sure the prop is not on backwards.