I'm no expert, not by a long shot. But here's my two cents anyways... take it or leave it.
much like you, i'm used to working far more frequently, with what i thought was great intensity. However my current program calls for no more than 3 days a week! It kills me. However, i've found that i'm SO DARN EAGER to get at it when i do get to go (to the gym) that my intensity has just SKYROCKETED!!!! I thought i was already giving it all i had... and i probably was, but i just had less to give because i was there so often.
i realize that doesn't really answer your question at all... just something to consider, see if the same is true for you.
Kenny