Earlier today, I did a Tier 2 run from Moorcroft to the Jelly King. From several levels of adventuring, through several different areas, I received a couple of Gel Drops, a couple of Gel Cores, and a Rocky Core, and a couple of other assorted low level drops.

I've noticed severe discrepancies in the drop distribution since release, and while they don't favour anyone in particular, it is somewhat beyond terrible luck when the ratio of drops one gets to the ratio given to all other party members is worse than 1:20, which is roughly what the above Jelly King run was.
I am estimating about the exact totals, but I was actually receiving less than 1 in every 20 drops, among 4 players. 1:4 would be ideal, even 1:10 could be within the realm of statistical error, but 1:20 is pretty steep. And pretty much every run I have done since release has been in the 1:10 or worse range.
I don't presume to call it a bias against me, but the fact that an apparent bias against any player can exist means that something is up with the balance of distribution. Especially since this usually means that one or two of the other players are getting a 1:2 or 1:3 drop in their favour.

The reason why I'm posting this as a bug report is because the drop system distribution was incredibly even and fair during beta, and since release has utterly collapsed. I'm not sure if this is a bug, or a rebalance, or simply the application of a different drop calculation system, but I would appreciate some clarity on the issue.