I’ve actually used the Sejoy Shaver before. For a <$20 rotary shaver, it wasn't too bad. It gives an okay shave, but you definitely get what you pay for. One thing to watch out for is the on/off button – mine got stuck after a few uses, and I had to use a paper clip to "unstick" it.
Overall, it’s a decent option if you're looking for something budget-friendly and don't have high expectations. It can handle light shaving pretty well, but it might struggle with thicker or longer hair.