I've seen great things and horrendous things with CFE223. I have a black hole weaponry barrel that really keeps pressures low, with 53 vmax and CFE I couldn't get under 10 inch groups and some were 14+", astounding really.
On the flip side though I got some 65 SMK to try with CFE and in my first test batch one of the loads had all the bullet holes touching and when I got some drops out to 300 yards it indicated I was getting speeds in excess of 3100fps with a 16" barrel, again astounded.
CFE223 has been the dirtiest powder I have ever used and if you keep a round chambered for a couple days in a fouled rifle the brass and bullet start to tarnish, along with some of the top rounds in your magazine.
CFE they say is short for Copper Fouling Eraser, Carbon Fouling Explosion would be just as suitable.