This mixer has audio issues. I have had mine for two years and it's finally getting worse.

The Left side is lower in volume than the right side. I have a friend who has the same problem and said it's a factory defect. Anyone else know anything about that?

It shouldn't be significantly lower - sometimes the meter shows 1 or 2dB lower but it's nothing to be concerned about.

Check that your faders are firmly seated by unscrewing the faceplate then removing and reinstalling each of the channel faders.

I am in the market for a djm-3000, but somebody said they are being phased out. Is this true? If it is, is it worth waiting for a new rack-mounted 4 channel?

The time to buy is when you need the gear. For now the 3000 is the rack mount mixer that Pioneer has available, I would buy one if I needed it now!

The 3000 is about the best 19'' reck mount mixer on the market.

You could also rackmount a DJM700 or DJM800...