I switched from the Alphatrack to the CC121 and have been very pleased. I came to really dislike the sound of the Alphatrack motor, since I am often mixing at low volumes (or mixing material with a lot of dynamics), so the motor sound really got on my nerves in some situations. That may seem silly, since all motors will make some sound. But there was something about the Alphatrack motor that really annoyed me. I also didn’t like the build quality of the Alphatrack. It just felt a bit too cheap for me. Even the buttons annoyed me on the Alphatrack… their loud click sound bugged the hell out of me. Overall, it just didn’t feel like a fine piece of hardware (for my taste) so I started searching for a replacement.
I was hesitant at first, but when I felt the build quality of the CC121, I thought I’d give it a try. The store didn’t have it hooked up, so I couldn’t listen to the motor, but just the whole package seemed better than the Alphatrack after physically handling it. The trial was worth it. The CC121’s motor is superior (although you can of course still hear it, but it’s not annoying to me), and then I found out you can also just unplug the power supply and the motor will simply stop, and the rest of the unit is still powered by USB, so I use it both ways. When I need the motor, it doesn’t bug me, so that aspect was a good solution. And the buttons just felt better to me. Those little physical things might seem small, but when you have to use it for hours on end, it matters. The build quality of the CC121 is definitely a full step better than the Alphatrack, but then you’d hope so for the extra cash. 
The CC121 delivers in the feature-set, too, of course. I do miss the LCD screen from the Alphatrack, but it’s more than made up by the 1 to 1 nature of the CC121 with Cubase. The CC121 just fits Cubase like a glove. I’ve found I’ve used it far more than I used the Alphatrack, and my workflow is definitely faster now. It makes Cubase feel a little more like a dedicated piece of studio hardware rather than just software now. It is “one” with Cubase, as opposed to just “controlling” Cubase.
I am annoyed by the reversed EQ, but I can understand why they did it that way. I would prefer if they gave us the option – maybe just a little software check-box on a driver preference page. They still can give us more tools like that with a software update! I hope they’re still paying attention! There is a lot of life left in the CC121, so I hope they still have development budget for new, even minor, features.
I also wish they had always-on dim lights as an option – that would not only be cool, but useful in a dark studio.
And now that I’m slowly getting used to it, I kind of wish for more Function buttons.
But basically, those minor issues aside, it’s a superb controller. Maybe the best single-channel controller on the market, if maybe a little pricey, but I think you’re paying for the improved build quality. The AI knob works on most plugins, although I’m still getting used to it. With the mouse in right hand, CC121 on the left, you can rock around Cubase like a madman… to me, much better than the Alphatrack.
As for plugins, I use typical, current plugins like Native Instruments stuff, Omnisphere, Arturia, FabFilter, etc…, and off-hand, I can’t think of a major, current plugin that doesn’t work with the AI knob… but I’ll pay more attention in upcoming sessions. I haven’t had the CC121 all that long, so there may be some issues with some plugins I have, and I’ve probably missed something. My guess is that it will work with most current plugins. Your mileage my vary. I haven’t tried it with tempo control yet.
I should probably read the manual… I just discovered that you can control the metronome with value knob/button, and now I use that every day. What other secrets lie within?
Basically, on a scale of 1-10, I’d give the CC121 a solid 8. It’s a bit short of perfection for what I’d personally like… it’s the type of product that spoils you for something that has even more potential, but that doesn’t yet exist. Some of that potential could be realized in driver updates (i.e.: dim always-on lights and option to reverse EQ knobs). Some of that potential is simply missing in the design (i.e.: no LCD screen, wish it had more function buttons). I think I understand why they chose to implement what they did, so there are trade-offs. For the most part, I think they made the right decisions, and as far as Cubase goes, the CC121 is the one to get, IMO.
Comparatively, I’d have to give the Alphatrack a 7. Maybe a 6.5. Why? Because it really tries to do everything right, and for the most part it succeeds in the basic design concept… and you can’t beat the price of the Alphatrack, so that has to count for something. However, the build quality of the Alphatrack annoys me enough that it has to take a hit that even its low price can’t compensate for. They compromised a little too much in physical implementation/quality, IMO. Plus, it is inherently a “generic” controller which adapts to many DAWs. That’s good and bad… the good is that it is super-flexible for what it does, and you can use it with anything. The bad (for lack of a better word) is that it pales in comparison to the CC121 when dealing with Cubase. The CC121 actually gives a natural, physical extension to Cubase in a way that the Alphatrack just can’t match.
Based on how well they did with the CC121, I’d probably end up buying a multi-channel version of it if they ever made one.
Finally, as for driver support and commitment for the CC121, the jury is still out. While I believe that Steinberg has improved recently, I will admit that old habits die hard… and the corporate culture at Steinberg has to show it has permanently changed. I hope it has, but you never know. Steinberg is a strange beast… inconsistent to say the least. They have provisionally earned my cautious confidence, and I think they’re safe enough to start buying hardware from them… So I caved in bought an MR816 and Yamaha N12 as well. PG, the main WaveLab developer, has already pledged support for the CC121, so that also goes a long way to show that Steinberg stands behind this. But I’ll still be slightly skeptical for another year or two before they’ve earned my complete trust. I’ve been burned by them before. Right now, Steinberg is on a good streak, so whoever they have hired to run the ship is doing a better job than what was going on before.
