Comments? Well I think it's very clever. I also think it's quite normal that this will sound somewhat grainy because you are in fact using a grain-like technique.... And I think it's entirely normal that it turns out to be hard to make a artefact-free brick-wall filter (see articles on how various DAW's handle re-sampling *cough*).

THE way to handle re-sampling filtering should be a sinx/x function ( http://en.wikipedia.org/wiki/Sinc_function ), modern hardware converters (which I gather you are after) often use a FIR filter, I think, and as I wrote in my previous note about this you could make one of those using LiSa. In fact once the update Dan just announced arrives I think you could basically feed this; http://en.wikipedia.org/wiki/Sinc_filter straight to LiSa's buffer.