Why do you want to spend time routing MDF for baseboards & trim? Go to most lumber yards or building supply companies ( excluding HD or the Lowes, I doubt if you would find any one that would know what I'm talking about ) I don't know where you live, but if there is a United Building Supply or Pro Built store they can help you.
They sell MDF base boards, and trim moulding in 14, 16 and random lengths. In Butte MT for example 16' Colonial base boards in MDF and primed is $8.45. To me time is money - the only thing I would gain is the satisisfaction that I made it, but I have better things to do with my time.