Vince,my 16 flew in both configurations and yes they needed trimming, I do not use a third fuel tank as I get 6 mins flying time with the main tanks and I have left about 500mil. I f you are going to fly flat out then you will suck fuel but I fly about 60% and do a couple of high speed passes.

If people do not have a third fuel tank and you have room up the front put in a bigger UAT tank.

regards
Todd