Thanks Alex for this incredibly versitile and good sounding tool.  As I'm getting more and more into it, I'm just wondering about the idea behind the weighting function.  At first I thought that for a "balanced" or dynamically "relaxed" mix it should be applied the other way around, i.e.  lowering the effect on the highs and lows and not emphasizing them.  After thinking about it for a while I came to the conclusion that maybe the idea is that compression should be applied more towards both ends of the spectrum, as the human ear is less sensitive towards the frequencies in these regions, thus creating less "stress" to the listener.  As you said this option is mostly experimental, could you shed some more light on this topic and your motivations for including this option?  Thanks!

PS: I should have also said that weighting in some cases does indeed work very well.

Spectral weighting is an estimation of energy our ears actually 'hear' in sound being played.

So, when you engage weighting, you should try to get a horizontal spectrum layout because that way energy our ears hear will be evenly distributed among all frequencies.  However, please bear in mind that this is an 'idealistic' approach, and may not always work well for real music material.