Depth of Options
Adobe continues to add a wonderful collection of features to this package. I don't have room to go into every feature, so I'll try to stick to newer ones and those I'd like to highlight. (You can get more background info by reading Jeremy Hanke's review of Adobe Production Studio Premium which included Audition 2.)
Version 3 offers improved multitrack editing with the ability to group clips together and edit them simultaneously. This allows you to move clips together, trim the ends, add/edit fades, and perform time-stretching on multiple clips at once. Also new is support for VSTi virtual instruments, opening up a whole world of sonic possibilities. I'd like to see Adobe include a few more sample VSTi's with the package, beyond the current 3: polysynth, bass and drums. This would just make it more complete, so those new to the concept can see how excellent it can be without having to buy another piece of software. MIDI implementation, though a bit on the basic side, includes a piano roll-style editor and should be just fine for most users' needs. If you're doing serious MIDI-based composition, you're probably not using this software for that anyway.
Improved mixing capabilities are also available with the addition of Bus Tracks. These tracks function like subgroups on a traditional analog mixer. They allow you to route multiple tracks to them so you can do additional effects and mixing to them as a group/stem. This is great for submixing individual drum mics then adding dynamics processing to the drum kit as a whole, or for routing multiple dialog tracks to a stem so all of the dialog can be mixed up or down with one fader. You can also use Bus Tracks as effects tracks (aka send effects) by setting up its effect rack and sending some of the sound from other tracks to it using those tracks' Sends feature. Something else that caught my eye while I was doing this is that each track has slots for up to 16 insert effects and 16 sends! Wow!
As cool as this is, one thing that did bother me about the Bus Tracks was that when I soloed a regular audio track, I still heard the feeds from other tracks' sends going to the bus tracks. So, for instance, when I'd solo a guitar track, I'd also be hearing the vocal track's reverb effect (which was set up on a bus track and fed from the vocal track's Send #1). This only occurred in cases where the audio tracks' sends were set to pre-fader. This is actually more akin to the functionality of a real mixing console, but having it automatically turning off other tracks' feeds would be a nice trick and should be possible in the software world. (I haven't noticed this being an issue in my higher end audio production software, and would love to see it addressed in Audition 4.)
Also, new effects and processing have been added to Audition's arsenal. The Convolution Reverb uses samples from real spaces in a process that basically "puts your track" in that space. This is great for recreating realistic acoustic spaces for dialog or musical instruments. The Guitar Suite effects offer many capabilities to get that guitar tone right without having to mic up a cabinet and waking the neighbors. The new Radius Time Stretching algorithm from iZotope greatly improves Audition's sound in this area and is used throughout the program wherever time stretching is offered. Finally, improved restoration tools like Adaptive Noise Reduction and Automatic Phase Correction make it easy to fix problems once thought to be show-stoppers that required a track to be re-recorded.
Additional features include a nifty surround encoder which is automatable with keyframing, batch processing, improved CD ripping, and overall better performance thanks to full multi-core compatibility as well as other improvements in Audition's software architecture that make things run more efficiently on any system.