I am registered in twenty states and many have PDH requirements.  The key flaw in most programs is not having a generous carryover policy.  Most states with continuing education requirements demand 15 PDHs per year, so a two-year renewal typically requires 30 units.  In order to ensure that engineers do not go long periods without PDHs, carryover points are limited.  

This is a short-sighted policy and here's why:

It is possible for a well-matched short seminar to boost the skills of a motivated engineer; however, all things being equal, the discipline, repetition, depth and breadth of a semester-long course with lecture, homework, and tests is far more valuable. 

In most programs, a college semester-hour is 45 units, so a single 3-credit course racks up 135 PDHs.  Even in states that permit 30 units to carry-forward, this would allow only 60 of the 135 units to be counted... leaving 75 units on the table to be wasted.  Any engineer that desires to upgrade or strengthen his skills will avoid the long commitment of a semester course and opt for the easy day-seminar or some on-line video course. 

Not every engineer's schedule permits the commitment required for a semester-course, but they should be encouraged where possible.  The profession will be the winner.