(1) Serato Sample - I got the 30-day demo. It has an excellent interface, and is very easy to use. Each virtual instrument uses a single audio file, and up to 16 cue start points can be assigned from within the file.
It works well using QuNexus to launch each cue, and a single cue can be put into "keyboard mode" to transpose it based on which key is played.
Unfortunately, critical settings are global. For example, all cues must set set to continuous or gated together, and all cues must be set to mono- or polyphonic together. If the cues are both continuous and polyphonic, there's no way to stop a note; they just build up forever.
Ideally, I'd like these settings to be done on a per-cue basis, and I'd like to be able to set an end-point so that a cue ends at a specific point.
I do like the idea of being able to grab specific sections of a file, but I think I'm going to keep looking. It's not quite worth $100, and it's the first thing I tried.