Got my 550 yesterday ($429 and 1 day with Amazon Prime - amazing!). Haven't been out with it yet - will cache this weekend to try it out and will report.
JessJoe, I had a Colorado 400t and returned it for the Oregon. Personally, I didn't like the rocker wheel and for the money I was spending felt that I ought to have the touchscreen. From what I have read, the accuracy on the Oregon is a bit better than the Colorado, but I have no definite proof. It did lead me to within 10 ft. of the caches I was looking for, though neither were under heavy tree cover.