My first (and only) cob got a burnout pretty quick, and I haven't picked up another yet.
I thought it was a great pair for the tobacco sampler it was sent to me with, some of those blends just don't taste the same in my current pipe.
The cobs they used to send out with samplers or "tobacco of the month" type deals were the crappy Chinese cobs, not even worthy of the cob name. They were very prone to burnouts, which is surprising, because I assumed they were lead-lined.