The folks in our wilderness SAR group use the Garmin 60CSx almost exclusively. A couple of team members have purchased Colorados and Oregons and returned them. (Yeah, REI!) The physical buttons make the 60CSx easier to use without looking. Also the 60CSx screen is more readable in a wider range of conditions.

When the 60CSx first came out it beat all other units hands down. It locked onto satellites faster and held lock better than any other unit. The difference was huge. At the time Garmin advertised that this was due to the SiRF Star III chip. It was unique in the industry and a huge leap forward. Now several other manufacturers make equivalent "massively parallel correlators." Garmin doesn't advertise the SiRF Star III any more and the rumor is that they don't use it exclusively in the 60CSx. We've seen no difference between early and late production units, so it doesn't matter. What does matter is that whatever unit you buy has a "massively parallel correlator", whatever that is. I don't know what the words mean in terms of technology, but it makes a huge difference in the ability of the GPS to figure out where you are.

By the way, for those of you who need California topos on your Garmin, check this link. A woman in our SAR group created these from USGS data.

http://www.vr6.com/gps/map-dl.htm