had my l5 running for over seven years now,with the doors open,the odds would be at some time my carbon monoixe alarm would go off-nah never has done,the gas heaters are a personal choice,and i feel that some don't like them,thats fine
don't knock it until you have tried it.
they have there uses for many jobs and does make life a little easier on a daily basis,but again don't knock it until you have tried it,the amery's are very good too had a week or so trying these out,both the amery and l5 are basicly the same inside the guts of it all,