The Good: Impressive stopping power. Modulation is simply the best available. Easily adjustable.
The Bad: The finned heat-sink pads are expensive.
I ran these brakes on a cross-country race bike for five months this year and came away thoroughly impressed. I had been using previous-generation Shimano SLX brakes, but these brakes blew those older models out of the water. The reach adjust is simple and doesn't migrate or wiggle. The increase in stopping power was immediately evident. After a few rides I also noticed that the modulation was superb. I never locked up a wheel unless I was trying to. I wouldn't hesitate to run these brakes on a trail bike, or even on a gravity bike with some larger rotors installed. They're the best brakes I've ridden. I didn't have to bleed the brakes during the time I owned them, so I can't comment on the ease of bleeding. The only downside I can think of is that the finned pads are very expensive. However, I ran my brakes with the standard pads and never had any issues with overheating or brake fade, so if you're on a budget you could skip the fancy pads and still enjoy the great feel and power of these brakes.