The Dyna-mite was an interesting hardware device released by the short lived Valley People Inc in the 80s, which was the brainchild of the great audio designer Paul Buff. It was perhaps the least expensive pro unit available at the time, mostly because it was supplied in a plastic box instead of a 19 inch rack mount. It did have a couple of very unique functions and sounds though, and Softube and Universal Audio have managed to emulate them all.
First of all, the limiter is about as kick-ass on percussion as you can get. If you want an aggressive sound that really smacks, this plugin can really give it to you. Most unusual is the fact that the plug (like the hardware device) also has a de-ess and gate/expander function, and like the limiter, they react differently than most of the other plugs that you're probably using.
If you want a plugin with some real character and you already have the UAD hardware to support it, make sure you try the Dyna-mite. It's $199, but I think it's worth every penny. Find out more on the UAD Dyna-mite site.