I have both the Garmin 60csx and the Garmin Oregon 550, the latter of which I use almost daily.
Both GPSr are extremely capable, and there are things that I like about each.
--60csx--
Superb unit in nearly every way, including compactness, accuracy, reliability, and features and battery life, and fairly inexpensive, and very, very popular. Screen is extremely usable in all lighting conditions. Menu structures are fairly intuitive, but easily learned. Toggle switch used to navigate menus and select functions is intuitive and reliable. The Base map included free is only fair for road navigation, and useless off road. I use the free gpsfiledepot.com topo maps, and have been very happy. Compass is two axis and very usable IMHO. The depth of features on these GPSr are far better than auto unit IMO. I REALLY LIKE THIS GPS! Bought it at Amazon with no complaint. I also have the auto windshield mount that worked fine until I got the 265wt.
--Oregon 550--
Also superb in nearly every way, including acceptable size, accuracy, reliability, data storage, and features (to the max!) and very usable battery life, though it is expensive! I accidentally submerged the unit (and me) in 5ft water and it had no ill effects. The larger, high res screen is much harder to see in bright conditions. Menu structures are very intuitive, and touch screen makes navigation great. I personally don't value touch screen that much. As with the 60csx, get the free maps as the base map is poor. Other features include a so-so camera, but it geotags photos, a great 3 axis compass. And for some, like me, I needed paperless geocaching ability, which it handles well, and this drove me to buy it. Otherwise, I would have stayed with the 60csx. Also purchased at Amazon with no complaints.
Of course, as people say, a GPSr is really no substitute for map and compass, and common sense.
If money is no object, and especially if you geocache, get the Oregon. Otherwise, the 60csx is a no brainer. You really must see them in person to make a choice in my opinion. I look forward to returning to the Bend to use them.
I do have another auto unit for the car, which is superb (265wt).
Have a great day.
Steve.