I was intrigued enough to try one of these this morning. My thoughts:
The bad: IT HAD ****ING ONIONS ON IT. WHO IN THE **** PUTS ONIONS ON A BREAKFAST SANDWICH???? I HATE ONIONS!

And since I have never in my long life been served a breakfast sandwich anywhere that had onions, I didn't bother to check for them, so I actually bit into one of the goddamn things. Ugh.
The good: After I picked the the ****ing onions off and angrily spat out the one I bit into, it was fine.
The verdict: Did it taste good? Sure. But honestly, it was nothing more than a greasy cheeseburger with eggs on a bagel. It was nothing special, and also a bit heavier than I like for a quick breakfast. I rarely get McDonald's breakfast, but when I do I always get the bacon egg & cheese biscuit. That won't be changing.
My personal favorite breakfast fast food sandwich is the Chick-Fil-A spicy chicken biscuit. It rules.