Roomparty, I too am in the market for an ANR headset, and fly the 737. I have borrowed and trialled two headsets from other colleagues. The Bose Aviation X, $995 and the Seinnheiser HMEC 25KA about $500.
In my opinion if you want the best then its the Bose. They are light, very comfortable to wear and a good fit. The problem for me as an FO in our airline is that we have to use elastic bands to hold the intercom switch on the pedestal on so that we can wear the headset on both ears and still hear each other as our 737s are not fitted with an intercom that can be left on "hot" all the time. Not all Captains are happy to permit this practice and the Bose is not very comfortable and quite aqward, to wear with one side not over your ear. But if you are the Capt. then you can inisist!
If its a problem for you then the Seinnheiser has the ability, due to having hinged earcups, to be worn to one side.
ANR is the business, obviously its important to protect your hearing but the difference in fatigue level is dramatic. You really won't believe the difference ANR makes its quite a shock the first time you switch it on them. I am still debating which ones to get, but for sure will be getting them from the US the price difference is huge.