I bought the Pentagon 1 based in the sheer volume of stellar reviews here, as well as my experience with Triangle II. So expectations were obvioulsy very high (for the highest rated instrument in the KvR universe!).
I'm pleased with the Pentagon and glad to have it on board. Some features that I really like: 1 page interface extrememly usable, well designed. You just stride right into programming. Compare that with the innumerable opaque faces of Dynamo, which I also just purchased...no comparison. Everything in Pentagon is more or less hard wired, but it's not problem because there are *a lot of wires* in the form of dedicated enevelopes and lfos for just about everything, and because of the outstanding MIDI learn functionality, through which my many-knobbed Z1 has become a dynamite Pentagon 1 controller.
Documentation is outstanding. I'm a bit of a programming newbie (though an old hand musician) and this manual is more complete, lucid, and concise than any I own. Rene should do a couple of writing workshops at Roland and Korg (and NI for pete's sake--the Dynamo manual is an uninformative embarrassment of quaint marketese. Please tell us what the g**&&*&amn buttons do!)
The sound. To me the oscs sound warm and rich, and I really like the filters. When I compare the naked Oscs with my Z1, the P1 holds up well. My dedicated softsynth machine has an audigy in it. I'd like to hear it through some real class converters. But there's no doubt that P1 has a sound worthy of the word "professional." I'm sure it stands with all the good VAs in terms of its basic modeling. I can't say the P1 has ripped my head off and replaced everything in my rig. I am a guitarist/songwriter afterall...
It sure is an elegant and good sounding piece of software, though.