I've noticed similar issues. Caching with a friend who has the 60CSx, I've seen my Oregon sometimes point to the wrong spot while he zeroes right in on it. It may be less than "50-75 feet" off, which isn't unreasonable for caching. I've also found that if I hold the GPSr still or set it flat on a surface for a few seconds, it settles out nicely. And the Oregon captures my own cache within 4 feet, consistently. I'm guessing it's an issue of obstructions, and differences in antenna sensitivity. And whether or not you use the "WAAS" (GPS signal correction) option.
But I've impressed my teammate several times by having the cache info at hand, including the clue. When we both know it's "under that bridge", the Oregon saves the day with its paperless feature.
If the quad-helix is so much more accurate, (which it is) then get a used Colorado online. It has a quad-helix antenna and WAAS and features paperless caching. The only thing it is missing is the touch screen. I'd rather take the accuracy and paperless caching over the touchscreen any day.