That doesn't sound to horribly bad. I know on many things, even if they are off by up to as much as 10%, you should still use the torque wrench. This will at least ensure all the bolts are tightened alike and all are uniform, so yep, I guess it does matter what you're working on.
How about a drop? Let's say the torque wrench is on a 3ft tall work bench and gets knocked off and falls to a concrete floor. How bad you think that will affect accuracy and should it be recalibrated after a drop? Have you guys done any testing to see at what levels or what type of abuse it might withstand and still maintain accuracy.
I know I've been in the middle of an engine rebuild before with 3 rods left to torque and dropped a click torque off the top of the motor that was on an engine stand. Just to be safe, I had it checked and it appeared to be just fine, but I lost 2 days using that wrench, and had to borrow a buddies. I then went back loosened and retorqued the other 5 rods with his wrench so I knew they were all uniform.