I always feel bad doing this especially when there's an IRROP situation and everyone is waiting in line. Then again if you fly enough to qualify for the Premier line, then you'll probably encounter a couple of IRROPs every year, whereas most of the people in the regular line probably only see something like this happen once every few years.
I know this will sound a little DYKWIA, but I hate to see non-Premier or even Premier members use the 1K/Polaris line at smaller airports just because the line is shorter... We all need to get somewhere, and if the agent is free, they'll call you over. No need for people to balance out the lines. /end rant.