I have a 60CSx and been doing geocaching for about 3 months now. I couldn't be hapier with my GPS.
Remember, the 60CSx is very popular, there are many people using and reporting problems and Garmin has been very good updating the firmware to solve them. In a few more months, the 60CSx will be even more stable.
You will have a better and tested GPS unit than others but that's up to you to decide where to spend your $.
Regards,
Luis Sismeiro