I'm sorry to you and anyone else who was looking for that object. When I took my site down it was supposed to only be for a week while I updated the backend, but life got in the way. Since most of the content was old, I left it down forgetting that my Max objects are not linked elsewhere. I'll hopefully have the site back up this week and next week I'm planning to release a slightly updated version of rm.slice
don't know about Roth' website, but afaik his object is modelled after the original [slice] object by Nao Tokui. You can find a 64-bit version of it here:
you might also want to try [vb.aubio~], which is a wrapper around 'aubio lib' by Paul Brossier.
it offers several methods for transient detection with much deeper control.