Practice cards for orchestra?

I am curious to know how many orchestra teachers use practice cards.  I do not like to use practice cards and I do not feel like they would benefit my program.  Students always play the best if they are self-motivated to practice and I am always trying to find ways to inspire my students to want to practice.  I do hold playing tests every two weeks...and I suppose the fear of playing in front of a class inspires frantic last minute practicing. 

After much Suzuki training, I have learned that every student really can learn to play a stringed instrument.  The Suzuki method turns practicing into a sort of a science.  If students are taught to practice as the Suzuki kids practice, they would see the fruits of their labors.

I came up with this practice record that I will pass out to students to teach them how to practice and show them what they should be practicing.  The blank boxes under "Mixed up Measures" are for students to write-in measures of pieces that are giving them trouble.  I want the students to focus on what needs to be practiced, instead of just playing through a line of music.  The students mark tallies with how many perfect repetition they play each day.

My plan is to have students staple this sheet to the front of their music book.  I won't require students to turn this in... but maybe I will accept it for extra credit now and then.