Remington gave them a run a few years ago (about the same time as they introduced the EtronX electronic priming system and rifle). They weren't received very well and didn't get very good write ups in any of the US mags I was reading at the time. Pretty expensive as well.
Its all good. I was trying to get a general feeling as to how people felt about them. Personally I reckon if your on to a good thing stick to it. The ones ive read about are varminting barrels, so no real need I see to go ultra light on a rifle you usually sit or lie down with as your usually perched on a hill, in the back of a ute or on a bench, unless your a silly bugger like me and walk around for a few hours, talk about dead shoulder!
Wasnt actually thinking of getting one, when that time comes ill be looking for a reputable barrel maker.
I cant give you anything scientific apart from to say with an explosion with the ability to kill or maim me going off right by my face, i feel safer with an ALL steel tube taking it out the proper end!
HEY As stated earlier Remington introduced a Sleeved barrel which never took off . Ive only heard mostly negative reports about Carbon Fibre Barrels I think Guns and Game would be the only source of a positive report . Even so it only had resonably accuracy for a Varmint Rifle . I myself would stick with steel .