Yes, Breakfree CLP failed me-twice. The two times I used a small amount of Breakfree to lubricate my SIG the gun jammed both times. It caused me some serious problems in a couple of important shoots. The only time I EVER had jamming problems with a gun was when using Breakfree. This is my personal experience and personal observations.
I also have heard a lot of stories about soldiers in the military having problems when Breakfree (whatever they called it in the military) seemed to cause jams. Visit websites like the website for Militec-1 where you can find stories about soldiers having their families send them Militec-1.
An old ex-Marine range instructor told me he did not believe in CLPs. He said you can't have a solvent and a lubricating oil in the same product. Perhaps his point of view is outdated because of modern technology but even some supporters of Breakfree say that cleaning is its weakest area.
All I know from personal experience is that my old SIG would function regardless what I used,grease or oil, except the two times I used Breakfree. Maybe it was just a strange coincidence but everything else worked-Hoppes, TW25B, Formula 3, Tetra gun grease, you name it. The only two times I had problems with jamming were the two times I used Breakfree. Is that just a strange chance occurance or what?