Metallurgy is the bomb. It makes even jaded musicians/producers sit up and take notice. It combines grind with grit with very cool delay and wraps it all in a package that has one of the spikiest gui's I've seen this year. It's easy to edit too - and be ready to save presets that you pass by on the way to your destination.
I've used it on everything I've done in the past three weeks and have yet to find a track that it can't spice up in some large or small way. I've even gone back to past tracks just for the purpose of seeing what Metallurgy can do for them.
The real beauty of it is that it can be truly vicious or nice and subtle. It's great when used full force on drums, but can give a bass line that little extra something when used gently through an effect send - like a pastel watercolor wash.
The $20 asking price is a steal. I would pay 5 times that for an effect of this quality. With the synths that Ugo has given us for free (Motion and String Theory are two that get constant use around here) you'd be foolish not to spend a double sawbuck on this.
I'd like to give it a 20 score in the categories 'Features', 'Presets' and 'Value for Money' but I'm not allowed. That's a shame really because this is the first plugin I've felt strongly enough about to actually take time out to review.