ANR - opinions vary, but I wouldn't be without it. I wouldn't pay what the manufacturers charge, either: there are some after-market kits that are better quality and value. There are also folks who will convert your headset for you. (I'm not one, but I do recommend Richard Holder's conversion!)
Some headsets are not compatible with some others - it's a bit of a lottery. Even DCs can be problematic.
Richard H and I have done some research into this (for other reasons).
1. If the problem is that plugging in your headset means that other folks can no longer HEAR, then the only cure is to change the earpiece inserts - the best way is to do the ANR conversion, since the inserts that come with that are well-behaved.
2. If the problem is that your microphone kills everyone else's when it's plugged in, it's pulling down the bias voltage and starving the others. That will only be a problem in aircraft with a common intercom supply to all the headset mike sockets. The cure is a resistor (usually about 220 ohm) in series with the mike lead, decoupled to audio with a capacitor in the 8 to 50 microfarad range.