We improved largely nat. We'll release this new version soon. The new technology is named AHD, which stands for "adaptive harmonic debugging"; if merged with microkernels it leads to incredible new features and opens to new possibilities.
I sampled a free plugin from voxengo at MAXIMUM drive. It would be an impossible task for nebula. I sampled AUTOMATICALLY and I got TWENTYONE kernels, (20 harmonics), perfectly matched (but less aliasing). This beast runs at 10% nominal CPU, so just a bit more than 1% of CPU of my i7 core (8 virtual cores, and 10% was measured on a single logic core).
it means higher distortion, better tube models, cabinets, guitar amps, heavy overdrive, better precision, reduced cpu load when tuned by the library developer, mixed techniques for sampling and cpu optimizations