I have not found a better method for putting on size than training a bodypart 2-3x a week. I have found that the UHT routine to be one of the better routines for hypertrophy.
any program you follow will only work for so long before you need to change it. and that varies by each individual from literally every workout to 6 weeks with the same program. if you are getting stronger and making gains then dont switch just to switch-ride it as long as you can then change what your doing. just my 2cents