Generally, I prefer WinAmp for MP3 playback. However the new 7.1 version of MusicMatch will encode the more advanced MP3 Pro format. Files ripped to the MP3 Pro format are still playable as a regular MP3 (it even retains the .mp3 extension). I was able to open the MP3 Pro files in WinAmp (which is not MP3 Pro compliant) and play it -though with reduced sound quality. So, MP3 Pro files ought to work fine on existing MP3 devices. I performed a non-scientific test to see if MP3 Pro is really an improvement over regular MP3. I ripped the excellent David Bowie cover of 'Cactus' from the new 'Heathen' CD (originally recorded by one of my favorite bands, the Pixies). I encoded it in several formats/bit rates. Here are the formats compared: 1. MP3 @ 128 kbps CBR LAME encoder 2. MP3 @ 160 kbps VBR LAME encoder 3. MP3 Pro @ 64 kbps CBR 4. MP3 Pro @ 96 kbps CBR 5. MP3 Pro @ 100% VBR 6. Original CD I have a Hercules GameTheaterXP soundcard with a digital coax out. That output is connected to my HT (DefTech speakers, Anthem AVM-20, Newcastle AM-9080 amp). Each file was compared to the original CD which was also connected to my Anthem AVM-20 via digital coax. I was able to switch back and forth between the MP3 input and the CD input with a single button press. The track was ripped from the original CD to .wav using EAC. The .wav was then converted to each compressed format. Standard MP3 formatted files were encoded with EAC using an external LAME encoder. MP3 Pro files were encoded using MusicMatch. 1. MP3 @ 128 kbps CBR LAME encoder The 128kbps MP3 is probably what comes to mind when most people think about MP3. It's suitable for headphones while working out but not much else, IMO. I could not use this setting for daily listening. File size: 2.733 MB 2. MP3 @ 160 kbps VBR LAME encoder This is how I have all of my digital music stored (approx. 4,000 tracks on a dedicated hard drive). This is a variable bit rate setting meaning throughout the track the bit rate can go up or down -depending upon the requirements of the audio information. This setting maximizes sound quality and hard drive space. The 160kbps setting means the encoder will not allow the bit rate drop below 160kbps -yet the bit rate can climb as high as the 320kbps maximum of MP3. Prior to the introduction of the Anthem pre/pro into my system I could not hear a difference between this type of MP3 and the original CD. For whatever reason, the addition of a quality pre/pro has made the difference very obvious: bass lacks the life of the original CD, there is a certain 'air' missing in the initial acoustic guitar at the start of the track, there is a definite loss of atmosphere (vague, I know but it's tough to describe without sounding like an ignorant HT magazine reviewer ). I could live with this format in most situations other than critical listening. File size: 3.903 MB 3. MP3 Pro @ 64 kbps CBR This one didn't quite match up to the VBR MP3. It was tough to tell if it was better or worse than the 128kbps MP3. File size: 1.367 MB 4. MP3 Pro @ 96kbps CBR 96kbps is the highest bit rate available for MP3 Pro. I tried very hard to hear a difference between this format and the original CD. Alas, I could hear no discernable differences. It rendered everything as the original CD did. Perhaps I need another upgrade before my system can allow me to hear a difference. File size: 2.050 MB (amazing!) 5. MP3 Pro at 100% VBR I honestly don't know exactly what this setting does. What "100%" means I have no idea. At any rate I could not distinguish this setting from the original CD or the 96kbps MP3 Pro setting. The fact that this setting yeilded the same audio performance at a larger file size means I won't be using it. File size: 2.910 MB In case you're interested, the .wav file from the source CD was 30.117 MB in size. I will be using the MP3 Pro 96kbps scheme to archive my audio from this point forward. I've been a fan of LAME encoding and I hope the authors of LAME wind up supporting MP3 Pro as well. Not only does MP3 Pro equal the source CD it also takes up less space than a standard 128kbps MP3! A new king has certainly been crowned, IMO.