I have a USGI lensatic. I don't use it much. The sights and mil scale comes in handy calling in fire but I really don't do much of that any more. In practical terms it really doesn't work any better or more accurately than the Silva.

Also the USGI lensatic compass is at least three times the weight of the Silva and it is a very bulky unit that doesn't fit neatly into a pocket. And now that the tritium has hit its half-life, at least once, the glow isn't much better than the twenty year old Silva. Unlike the Silva, which can be exposed to light and recharged, the tritium in the USGI lensatic can't. What you have is what you get.

Now if I was going to be parachuted into Congo alone I wouldn't carry a Silva, I would carry two. Just in case I lose one. And both together wouldn't weigh as much or take up as much room as as one USGI lensatic.