This is the best piece of software to limit connection speed.

The other one I know of out there is NetLimiter. Since I have used that I can only compare DU Super Controler to that.

First, I'd like to note the improper spelling...
Its CONTROLLER not CONTROLER...

But that doesnt change the quality of the program.

FIrst off, if you look at the screenshots here, the interface is fabulous. Its big, its clear, and its easy to navigate.
The best part of it is that you can see what it is connected to. And when it is connected to a server, the application can be expanded to see the connection(s).
So for example, with AOL Instant Messenger, right now it is connected to 205.188.10.24:5190 and oam-d14b.blue.aol.com.

The really nice thing is that one can choose to limit the whole computer, a single program, OR a single connection.

The only thing that I found a problem with the program is the specification of the speed limit. Don't get me wrong, it is quite easy to change the limits...very easy. A single click and you are ready to go. The problem lies in specifying a number and the sort. By default everything is set to Unlimited. When you click it you can type in a value, or you can use the up or down arrow to increase the value. The problem is that without otherwise typing in the KB, or MB, or GB suffix the program takes all values as bytes.
So for example I was limiting something to 12 KBps upstream. I click the box type in 12.00 and hit enter. It sets it to 12.00 Bytes. The only way to get it do KB is to either type in the number of bytes, so in this case 12,288 Bytes, or manually type in "12.00 KB". Its a real nuisance. Since development of this is pretty much at a standstill I doubt this will ever be changed. But I can deal with it...

On a side...
DU Sper Controler.exe is seen twice in memory.
844 KB...2,568 KB Virtual
7,932 KB...8,992 KB Virtual