I use a high-pass filter a lot when I'm producing samples, mainly to remove VLF, but something high-pass covering the whole audio range would be nice to complement the existing low-pass filter in Decent Sampler... It's a classic 70s technique (ARP Odyssey, Roland Juno-106 et al) to have a simple HPF before the LPF, although modern polys like the JD-08 seem to have forgotten this.