I was under the impression that the RR version was salvaged from lighters rather than being a custom built object.

Personally I carry a bic (simple, one handed, intuitive for others, the flame duration lets me do other things (light a candle for example), cheap) and a firesteel (nearly infinite sparks, hot enough to ignite improvised tinder) for back up.

I can see how the RR 4 finger and the sparklite get advocates, they are tiny, light and one-handed, just my my thoughts