I don't normally write reviews, but I've just bought this and I'm really impressed with it.
Like many people I have problems with sibillance in my voice recordings. In the past I've tried various plugins including ToneBoosters De-esser, Spitfish, Sleepy Time DSP Lisp and a few others. I quite liked most of these, but none was really perfect. I tried the demo version of FabFilter DS - everyone seems to rate their stuff very highly. It's really good, but it's also really expensive.
Then I found this product. I'd never heard of HoRNet before - I found them because they were giving stuff away on the Computer Music Magazine DVD.
The plugin is based on the usual compressor method of de-essing except that it splits the high frequencies in to 6 separate bands and seems to apply compression to each separately - so it takes an existing method and improves upon it.
The controls couldn't be simpler. There's no threshold controls to bother with. It's just an Amount of De-essing control and a Wet/Dry that lets you add back some of the original signal if the plugin takes out too much.
What does it sound like? Perfect! I couldn't believe how good it sounds. With other cheap/free plugins the de-essing didn't sound natural. The esses sounded conspicuously squashed and unnatural, or it sounded lispy before it took out enough of the ess. But this sounds just right.
Caveat: I've only tried it on my own (male) voice and only for spoken word because that's what I do. But the speed of the compressor seems be be tuned just right for my personal brand of sibillance.
Conclusion: for the price, it's a steal. It's stupidly cheap and there's a demo version you can download and try. I can't think of how it could be better, so I'm giving it 10/10. It might not have the fancy graphics of the upmarket offerings, but it does the job really well and fills a gap in the market at a very affordable price.
Update: The user interface has been updated slightly for version 1.1. It's now got more bands - which I'm guessing may be useful with female voices. And each band can now be separately turned on or off. I haven't tried these new features yet, but they seem to make it a little more flexible.