Useful or Useless?

I don't know how many of you use a linear compensator on a rifle. The idea behind such compensators is to direct the blast forward of the weapon instead of to the sides as is normal for most muzzle devices. You can see where this would be a benefit for someone shooting at a range where shooters are crammed in quite close beside one another, or other situations where shooters may be operating in close proximity to each other. But what if there are times you want to also keep your standard flash hider?

    The Firearm Blog reports (announced?) that Strike Industries is releasing what they call their A2 Blast Shield which is designed to fit over the standard A2 flash hider, and act like a linear compensator "to reduce side concussion and redirect muzzle blast forward, this blast shield is geared toward both professional and civilian shooters looking to enhance comfort without replacing legacy muzzle devices." The article (press release?) continues by noting that "[r]ather than removing a functioning A2 device—which can be difficult or even damage your rifle—this new blast shield is simple and risk-free to install." Given the sometimes difficult nature of getting the timing correct when installing a flash hider, or most people lacking the equipment to hold the barrel and receiver in place while cranking down on a crush washer, I can see how this could be useful to some shooters. But what do you think? Useful or useless?