Coined LFR Lei Shen over a dozen times and on normal 4 times for the UVLS trinket for my lock and gotten nothing but gold so far. We just started heroics a couple weeks ago and I had to pass rolling off heroic bosses just so I can get that damn trinket first. This is really pissing me off.
Everyone will have differing results with these coins. I've had pretty great luck with them. As a plate dps coining feather and rage, helm from DA, polearm, a couple of tier pieces. It really is good when someone has a good streak on coins since it frees up distribution for other raiders (particularly in 10 man) - and especially so with tier tokens. I hate having to do dailies to get the charms, but when you do get loot it's great (even with the frustration that goes with not getting something for a few resets)