[shorod]

Are you referring to a strut tower brace versus an anti-sway bar? The strut tower brace will connect the tops of the struts together rigidly. This keeps the tops of the struts from moving under hard cornering loads. Such loads are probably unachieveable in a Corolla.

The anti-sway bar connects the lower control arms of the car to one another using somewhat of a torsion bar. The theory is if one side of the car starts to lean/droop, the anti-sway bar will lift up on the opposite lower control arm to drop both side of the car somewhat evenly. I'm sure others can explain this better or link to a site that explains it. Most cars, even small econoboxes, use anti-sway bars, often front and rear. You can improve handling performance somewhat by going with a larger diameter anti-sway bar.

You really need to find someone knowledgeable in front suspension/steering to inspect the front end of your Sentra. It sounds like you might have worn inner and/or outer tie rod ends, or worn ball joints. Any of these can make the car unsafe to drive if ignored for too long. Any shop that performs wheel alignments should be able to inspect these components.

-Rod