Amazing module with a price that cant be beat.
I have owned pretty much every drum module on the market, including the Roland TD-20. All of them had pluses and minuses that you have to work around. With samples that ranged from just okay to amazing. The Alesis DM 10 basically takes what was offered in the TD 20 and expands on it in unlimited ways.
One, USB. Quick connection to any computer, which also allows for upgrades and add-ons to the unit itself. Not to mention quick midi.
Two, Unlimited samples. The unit can be loaded with both first party and third-party samples from some of the biggest companies known to the drum market. Companies such as: BFD and Toontrack. Samples that sound as good as or better than any sample in the Roland TD 20. Which can only be expanded with other drums sampled by Roland itself. The thousand plus sounds in the unit off-the-shelf, are very well done and sound as good as any acoustic or electric drum out there.
Three, 12 TRS ins that can be expanded to 24 by using a splitter on each of the inputs. Therefore by connecting 24 pads, you can have 24 different sounds assigned to 24 different pads... Or you can just use the inputs as they were intended by connecting 12 pads, each with multi zone recognition. For me, this configuration was absolutely necessary in my studio. Allowing musicians the flexibility of having every drum sound they could ever need, right in front of them, assigned to each of my 24 pads. Imagine having three different 8 piece drum sets playing through one unit at the same time, You can do it with the DM10.
Four, Uncompressed samples. Which means full dynamic range without compromise.
So then, you ask what doesn't this unit do that the TD 20 does? You cannot change the drum size or the room size and shape. You can choose different drum sizes in the menu system, but you can't change the size for each drum manually. The room size and shape isn't all that important to most people, so it really is an unnecessary feature even in the TD 20. Other than them two features, there isn't anything that this can't do that the TD20 can.
Five, price. The TD20 can be had for around $1000 on eBay. The TD30 will cost around $2200. With this unit offering more functionality than those units... it's hard to pay for the name. Sure, there are things that you can do with that unit that this cant do. There are things you can do with this unit that the TD20/30 cant do. Though it's not $1200 or more worth of functionality. It is settings that arent all that important in the real world to most people. Settings that can be replicated off board for pennies on the dollar.
Six, a great onboard sequencer that allows for uncompromised control over your recordings. Simply record your live playing, go back and fix any offkilter beats in the on-board editor... Then record your masterpiece directly to your DAW... or simply drag-and-drop from/to your computer.
Overall, I recommend this unit over the TD 20 and TD 30. The ability to load and save sounds from third-party manufacturers allows for an endless supply of drum sets from some of the greatest drum manufacturers around the world in uncompressed, uncompromised quality. What you save in money, could be used for extra drum pads or other studio equipment.