It serves its purpose nicely. It's cool that I can throw on headphones without needing to plugin in a power cable or guitar cable. Sometimes I just need some sort of amp (regardless of quality) to come up with ideas, and that's what this is for.
I got the classic rock model which I believe has a gain that's too sensitive. It's either all the way on or invisible, with no in-between.
This thing is great for practicing, but obviously serves no other purpose.