I have an Oregon 400t which is amazing and I am jealous of you for getting the 550t. I hope it is even better than the 400t. As regards your query about City Navigator, it is worth pointing out that the topo maps supplied are good but will only point you in the right direction, ie in a straight line, they won't give you a route. City Navigator will do routing by road so what I do is to enable Navigator to get me to the area, perhaps the recommended parking area. This is much more useful than using the straight line only topo maps, but once you are there and on foot, disable City Navigator and use the topo maps. It works great for me and should do on your 550t. Good luck!