As per post 326 I have completed some initial testing - dexterity vs perception. It's not a huge test, but for those who will say "Oh you should do a bigger test", perception gains account for a very small %age of hunting skill gains and it ain't easy finding them! Anyway...
Method
I waited until I got a dexterity or a perception gain on a hunt. I then finished killing that mob, and without moving dropped a bomb and a probe in that order.
I then killed every mob in the small radar (if any) AND the next nearest two mobs.
Any tests where I died, or someone killed the nearby mobs before I could, or one of the mobs was too tough for me, or where I gained a perc gain before the end of a dexterity test (or vice versa) were declared void.
Results were gathered over several hunts on several days. Some dexterity gains were not followed up as there were approx twice as many dexterity gains as perception ones and I didn't want to follow them all up.
Results
After perception gains, 8 out of 17 bombs hit, and 8 out of 17 probes hit. (They did not hit in tandem, it was random).
After dexterity gains, 0 out of 14 bombs hit, and 4 out of 14 probes hit.
After perception gains, 3 out of 17 times I got a "good loot" on a nearby mob.
After dexterity gains, 2 out of 14 times I got a "good loot" on a nearby mob.
After perception gains, 6 out of 17 times Spawn's theory was proved correct in one or both ways.
After dexterity gains, 2 out of 14 times Spawn's theory was proved correct in one or both ways. (Obviously Spawn didn't say it worked with Dexterity gains but you get the idea of what I am saying!)
My Conclusion
I think that perception gains do let you know about ore and enmatter in the ground directly below you. Whether that information is worth knowing is open for discussion.
I also think that perception gains appear when you can see somebody exactly on the inside edge of your large radar, and perhaps on the outside of it to.
I don't think perception gains have much to do with telling you about future mob loots or future items in loot. But I do think that perception gains do tell us something else - a third thing - maybe that there is ore or enmatter somewhere near you. Or perhaps some perception gains are purposely given to us as red herrings. There could also be a timer as previously discussed on this thread, and this could be set to something like 120 seconds (that is a total guess so pls don't bother asking questions on that).
Forrest
PS I did rebomb/reprobe when I got a hit but the percentage hit rates from that after both perc and dext were so small that I would not recommend it. (Something like 4 out of 20 hit).