I would certainly double check the bleed job and make certain of the rear brake adjustment so the pedal won't have to travel as far and might make the difference with the booster.
keep in mind too, when you bleed the brakes the pedal travels further than normal and may have possibly damaged the diaphragm in the booster. Slim chance but maybe possible. Does the booster hold vacuum? it should as long as the check valve is good. Also check the vac source for any possible issues.
Hope you find the problem.
MCR is real close. You're going, right?
