With a THD rating of 1% at its rated power and a S\N ratio of 80dB it is most likely a very noisy amplifier and will certainly "sound" different then a quality amp. the 1% THD can actually go up as power drops.

For free how can you go wrong, if you don't like it swap it out at one point. I personally would try not to make extra holes in the vehicle tho in case I wanted to change it later.

You may not even be able to hear the noise or THD over road noise anyway. Let your ears be your judge.