If this product was not a commercial one, my rating would be higher, but when I've had to pay out up front, I expect a little more from an application.
I have used some of the competitors (Remository, PhocaDownload, and jDownloads) but none of them really met the demands of a new site that I am working on. After reading through the description and favourable reviews of Skyline, I thought that it might be worth trying for $25.
When I first installed it and ran it, the software reported an error. It was nothing serious - a deprecated command in one of the licence functions. I was able to find and fix this myself, but it wasn't a great start.
Overall, this component doesn't really offer anything more than any of its free competitors and certainly didn't meet the needs of the site that I'm trying to produce. I would caution anyone thinking of paying good money for this to have a serious look at one of the other packages first.
It seems that the service provided by Skyline is pretty good. I haven't bothered with it because I was able to fix the problem myself, but if you're not familiar with PHP, it may be worth paying something to get help when something goes wrong.
However, I've always found the non-commercial suppliers to be very helpful when there are problems so, for most people, I'm afraid I really wouldn't recommend paying for this package.