Great that you find a accuracy margin of 30% useful for determining whether to drive or not but as I said I am looking to fine tune my diet so I need much more accurate data.
For me having a reading with a 30% margin of accuracy just doesn't allow me to fine tune my diet.
I could actually be at 6 before a meal but test at 5. After I eat I could really be at 8 but test at 9.2.
Bad data leads to bad decisions so I think I will just cut out bread, potatoes and...
If you are going to make decisions about your diet and health based on glucose readings then those readings need to be fairly accurate. If the above is true then these monitors would seem next to useless.