I have one on my Remington 700 PSS 300WinMag.
I actually went and got it after finding I needed just a smidge more stock height to use as a cheek rest. The soft material is also nicer on the cheek compared to the feel of the fiberglass/synthetic stock.
I'm actually waiting to buy an adjustable McMillian A3 stock and then I likely won't need the Eagle cheek rest I have now.
The only downside to the thing as I see it right now, on a long action it is possible for the bolt to rub the cheek rest if you have the cheek rest mounted too far forward. It is also hard to remove the bolt with the cheek rest installed.
On a short action I doubt it would be a problem.
As for Blackhawk, I'm starting to shy away from them more and more with each passing year. Their stuff keeps getting more and more expensive and it's hard to deny the reports of things being made overseas after Blackhawk rips their designs from other folks like Eagle or London Bridge.