Your are right midhillbilly it may be behind but for 90% of the fishermen out there there is not enough difference in the two to warrant another $1000.00 for the plus. The one I have now does everything that I want it to do and more. They are chirp units also. If you got another $1000.00 to spend then then get the plus and if you want a good simple to use unit that will meet most people's needs then it is one heck of a buy.