I have had a few of these things for a few months now. I used to have the original Mackie Control Universal system before it was all upgraded to the Pro versions. The extender Pro version is honestly not all that different from the original version. However, they are physically shaped a little bit different, and it would look very weird to have those disparate units hooked up. I have heard that you can use the old extenders with the new MCU Pro main unit though, if you are on a tight budget. These units do not benefit from the new USB functionality of the main MCU unit. These extenders still have to connect to either your MCU main unit or a MIDI converter box via the usual MIDI cables. The encasement on these is now a very stylish brushed steel, and the LCD screen has been much improved. The faders on this extender are authentic touch sensitive Penny and Giles faders, which are arguably the best motorized faders made today. They are very quiet, unlike the Behringer control surface which is kind of noisy. The pan pots on this are nice, and there are LCD indicators wrapped around it to help you keep in mind where it's positioned. The main LCD screen on the top of the unit will read out the track names you have entered into your sequencer, which is one reason why this Mackie system really beats out the competition. The usefulness of the control surface is severely limited if you have to keep looking up to the screen to figure out what each fader controls. With this surface, it's right there on the LCD readout. It's very solidly built, and is larger than it looks in pictures which is nice. I love this product, it's a great value.