I want to preface this with the fact that I don't have my dubia colony.. yet. But, I have been doing a lot of research and reading on one, which is what convinced me that I NEED one.
From what I understand, you can control the amount of offspring your colony produces, fairly easily. If you notice that you have WAY too many dubia, you can feed off some of your adult females. The females are the queens of the colony and they are worth gold! You only need a few males to support many females, so when/if you decide that your colony has too many, you can pluck off your females. I saw someone on here 'estimate' that a female can produce about 15 nymphs a month (this was a conservative guess), so if you need 50 adults a week for feeding, then you want about 200+ per month. You would need about 15-18 adult breeding females to support this amount at any given time. Of course this is all an example. I don't know how many adult dubia that an adult beardie will eat (and I'm sure it varies from beardie to beardie, too!).
Does that make sense?
As for those crazy fast Turks, I don't think its as easy to control, but I don't know.
But please, if anyone (with some REAL experience with these guys) can correct me or exaggerate, I'm sure it would be appreciated!