I daddywpb: Welcome back, I thought we might have lost you to FEMA.
think the big gain is in the new SiRFstarIII chipset. It is designed to work indoors, and under heavy canopy. It should provide more and faster satellite lock time in heavy cover as experienced by those who live and hunt in moist climates. That along with the ability to save unlimited mapsets make it very attractive. But that is of little value to you.
For you the only gain would be the faster and stronger chipset. If you are satisfied with your 60CS it may not be worth the outlay.
I have a similar dilemma. I find the new units with the SiRFstarIII chipset, and the micro SD cards very enticing. But I am getting good service out of my other units. I would have purchased a 60cx or 60csx two years ago when I bought my 76C if they had been on the market. My thought is that if you have a model that was introduced five or six years ago you will gain a lot.
The bottom line is I cannot justify it. Also my low cost Gilsson amplified antenna is great on the road.
A question comes up regarding buying now and being first on the block or waiting six months. At times I think it is wise to wait and let them shake out any bugs in the system. Garmin has already issued one software update dealing with compatibility with memory cards from different manufactures. We have seen the same type of problem each time Microsoft has upgraded its operating systems. The 60x and 76x series gps sure fit the mold for my dream gps.
P.S. There should be a big gain for those who navigate the cement canyons known as cities.