Never had a problem. I have paid a couple of times, because the author deserves it. Worth every penny.
Sometimes I use it free, I feel like I'm stealing. Even in the early years, when I am sure eBay made it as difficult as possible to use api's, Gixen worked smoothly and without any problems.
I always thought the interface was a bit clunky, but it is clear and simple and does exactly what is asked of it. guys, if you need your UI redesigning, I would love to give it a try.... gratis of course.