While many VSTis contain their own arpeggio features, this external VST takes things quite a bit beyond the normal up/down/rand style of pattern. Its main focus is to produce MIDI patterns given keyboard input (usually in the form of chords). In this respect it starts to resemble phrase generation systems such as Korg's Karma etc.
Installation was simple and the tutorial videos on their web site get you up and running quickly. The UI is large and clear. Functions are well presented and the preset browser makes navigation very simple.
To my mind its biggest selling point was the extensive preset patterns provided. With over 1000 patterns in well organised categories, you will find plenty of usable and creative ways to process your MIDI input. The presets cover many bases; melodic chord work, bass lines, drums etc etc and many styles; classical, rock, dance, world etc.
At the moment the main negative point is the lack of a manual, but their website has handy tutorials and posts on KvR have indicated a manual is in the works.
If you find yourself in a bit of rut composition wise, this plugin could very well unblock those creative juices again.