Yes, there can be important differences even though extension tubes contain no glass. The main advantage of better tubes such as Kenko or Canon is the electronic contacts and aperture linkage, which let the camera and lens communicate normally for metering and aperture control.

With very cheap no-name tubes, those contacts are often missing, so you may lose metering, aperture control, and possibly autofocus. On a Canon 50mm f/1.8, that matters because the lens does not have a manual aperture ring, so cheap tubes can be awkward to use. You may need workarounds just to set the aperture, and manual focus is often necessary anyway for close-up work.

Image quality itself is not reduced by the tube, since there are no optics inside. The tradeoff is usability, not sharpness.

So if you want convenience and proper camera-lens communication, Kenko or Canon tubes are the safer choice. If you are comfortable with manual operation and experimenting, cheap tubes can still produce acceptable results.