I have to agree. I served from '03 to '07, and deployed with the M4. I've had relatively few issues. Overall, I would consider them to be exceptionally reliable. Most issues were due to the individual rifles' gray whiskers, and arthritic bones. The newer and/or tighter ones, I had the utmost confidence in.
Furthermore, even the M240 can have malfunctions when shooting at a cyclic rate of fire... and it IS designed to do that. After 5 or 10 barrel changes, you've shot enough ammo (belts that carry all manner of dust, sand or other debris into the action) to begin to gum things up. Given, that is a lot more rounds downrange than was mentioned in the article, by the M4s, but likely comparable when considering that this is somewhat exceeding the intended or practical design limits of the two TOTALLY different platforms.