This novena has increased my devotion to the Rosary. One of the reasons I got involved in setting up these Rosary Novena threads on CM (several good people began promoting this devotion on CM before I got involved in 2011), is to participate in promoting devotion to the Rosary. All who participate and contribute are spreading devotion to the Rosary.
As for intentions, most of mine are spiritual in nature. Praying for virtues, for a holy life and holy death, help with defects of character and habitual sins, also spiritual benefits for others (I try to be open here "bless and help so and so" because I cannot and should not prescribe what they need - God knows best), etc. I have asked for temporal intentions as well. The first time I prayed the novena was during lent in 2011. I'd been unemployed almost 2 years. I prayed for a job and started one the Monday after the Novena concluded on Divine Mercy Sunday. Recently, I started asking a confessor or spiritual director to suggest an intention which has nothing to do with me. That's been helpful. One of my intentions is always everyone who's praying the novena with us and for all their intentions. I also add all of the prayer intentions posted on CM.