Well, maybe this is just small sample size showing, but here's my personal experience from the other day.

I needed a Beadeaux Coffer Key for my WHM AF gloves. Went down there with a THF friend of mine, and we spent close to 2 hours killing the Quadav, getting TH to proc up to 6 on most kills, and saw only a few gold beastcoins and a waterga III for our trouble.

Few days later, we went back, and noticed it was a full moon. We cleared the first room and around the Mute, and set off to the east. First quadav we pulled from around the Afflictor, bam, coffer key. So we decided to finish clearing the area, maybe get a Flood or Water IV. Next mob: Bam, another key. THF took it and popped a coffer (I was on DRK at the time, so couldn't pop it for gloves). We kept going, and got 2 more keys. So, on a full moon we had 4 keys drop in a matter of about 20 min, while a few days before we spent 2 hours getting nothing. Just my $0.02.