It's actually about all the coin quests, but the silvers are what I'm poking around with at the moment.
All of the coin quests work like this:
* Get the quest to kill X of this, Y of that, and maybe some other things.
* Kill it all and hand it in
* Get a bit of XP, some Kinah, and a coin
* Collect enough coins and hand them in on a random piece of gear.
So I figure that if I'm going to be running back and forth through an area that has mobs to fill the coin quest, then what the heck. Do it along with the other quests that you're doing and hand it in when you're back by the quest giver.
The XP award isn't worth it if you're not going to be mashing those mobs anyway. Neither is the Kinah award, if there even is one for that quest. But is the gear worth anything?
I handed in 6 bronze coins in Eltnen and got a nice dagger, but the one I was using was nicer. I expect that will be the case with all the bronze coin awards. If you're keeping your gear up to date (green or better) then the award is better off sold or disenchanted.
I've heard that the higher level coin quests actually give you decent gear, so how about the silver coins?
AionForums has a post that basically says that you'll get a Rank X Soldier Weapon, which is Ok, but isn't as good as crafted or decent dropped items.
Care to add a comment if you've handed in coins or silver or better? What did you get as an award?
update: handed in 16 coins, got a blue Shield of Rank 6 Elysean Soldier. Nice. Can't use it, but still a nice reward. Guess I'll keep doing coin quests.