I bought a RSK mini from Aeromedix and so far it is great. I don't have any experience with field-sharpening a knife. My understanding is that S30V is a very hard steel. I would like to get a sharpening device that will:

1) work well on S30V
2) be as light & compact as possible; I want to be able to carry it as opposed to only using it on a workbench
3) is reasonably simple to learn to use properly

What's been working well for you guys?