If you feel you are a good enough Rider to be out on the road forever with just a Permit...then you should be a good enough Rider to take the test and get your license.
Taking a Riding School Class can not only help you get your license easier, it usally helps to lower your insurance as well.
Way back when, I took the book test and had to do the same course as they had for car test (instead of the three-point-turn I had to do a U-Turn). It was simple and I've always had it since.
It could also be that some states (other than yours) will not honor your permit after a set amount of time, but I'm not sure on that.
In any event......Take the test and get the license.