cmh lamps? anyone use them?

I am comming up on time to replace my hps lamps and was wondering if anybody has tried the CMH lamps? from what I have read they are made by GE and Philips and have a wider spectrum than the hps lamps. They claim that the useful lifespan is longer as well as they don't degrade like the hps lamps do over time. Any input would be appreciated. Thanks