Thanks catymag. So for an upgrade to my 3450 and staying with pre-2014 models, the 3597 or the 2797 seem like the obvious choices, and for the Oregon 450, the Oregon 600, Montana 600 or the Monterra. I have seen some posts here and elsewhere that imply these models are also affected by the authentication change for later firmware updates-is that the case, or do any (or all) of these still read unlocked maps with the most currently available firmware (as do my current models)? I have been comparing these against each other to see if the improvement on the newer models is worth the cost of an upgrade-not sure it is justified for the 3450 (except for the larger screen on the 2597), but the brighter screen and GLONASS capability are pretty compelling reasons for upgrading the 450 to one of the others-the 450's screen is pretty dim, even when not in direct sunlight, which is frequently the case when on the trail.