To eliminate the latency, you have to increase the "start" control to abour 35 ms. You can move it to 50 ms to completely eliminate the latency but then the guitar starts sounding more pianoish. Ample's explanation iirc is that a guitar string takes some time to get up go from 0Hz to whatever freq the plucked note is at. The "start" control provides for that realism. But when played on a keyboard you get latency as a result. Moving it ahead to 35 gives enough realism without noticable latency. When playing back recorded music yoh should dial "Start" back to 0 for maximum realism. Not sure I totally get how this works. Maybe real guitarists compensate for this subconciously?? 

I'll second FilterSweeps comments. Ample sounds quite good - and it wasn't until I messed with the start that I realized it has real potential and acts quite well with Sonar Pro. I need to look into the release sample ends of things. I sold my Kurzweil Midiboard a few years back and it was really great at generating and manipulating release velocities.

Ample sound guitars work fine in SPLAT, I have used them to correct errors in live takes obviously matching the guitar used they also give quick tech support if you have any issues.