As I noted earlier in the thread, we placed the tape there to keep the airflow over more of the card, rather than allowing it to bleed away.  I always appreciate that members are willing to spend the time to go through and do their own testing, but our VGA team also has a much larger sample size showing that the acetate tape results in better thermal performance for this particular model.
 
@slurm1 - I'd recommend keeping the tape on, as you won't see a performance increase in the card by taking it off.  However, you can usually improve the GPU temp by replacing the thermal paste, as adelli noted here in the thread.  Taking the tape off, on the other hand, would likely increase the VRM and memory temps.