Boring steroid debate again, but reality is, it'll never go away.....
In the pro ranks....have things really changed? Both pro and then USADAs UFC...
For example.....the final of the 100m in the Olympics....you really think these guys aren't or don't use PEDs? They have USADA right?!
So the UFC has this new testing....there are always going to be fighters beating the system....but how many? Sure....it's much harder, but there are some damn good doctors out there!
Also, apart from events which have incorporated testing....are the pro ranks a free for all up until the UFC and other top orgs. Are there fighters building a good career using PEDs to only have to stop when they sign with an org which tests?
Also, kickboxing.....and grappling. Are fighters building good careers for themselves and using PEDs? Is it fair?
Basically, how much are PEDs really getting stamped down upon? 
It's better than just leaving it to the ACs, but you'll never catch everyone. There just isn't enough money to do the amount of testing. I mean maybe if they showed up at everyone's house, every day, at a random time, they'd bust 99% of users, but that's obviously not possible.
Of course they'll never catch everyone, but they are catching some, and I would guess many fighters are reducing PED use because the penalties are so severe.
Most ACs don't have the authority to do out of competition testing.