Stanton;

Actually, you wind up with more problems with MPI than with TBI because the fuel is put in exactly same on each cylinder (assuming untrimmed). Any difference in airflow not only affects your charge volume, but mixture also, as the fuel is fixed. With TBI the mixture is set before the runners, so it is consistent, leaving you only with charge volume issues.

With a carb, you get both issues, as you get some mixture issues back because of carb signal issues with a single plane.