This is a tough one! It's a little like having two girl friends. Both their brains operate in the same manner. But the exterior is a little bit different, and you have to make a choice.
Garmin GPSMAP 60CSx PKG incl USB PC Interface cable 010-00422-00 $369.95
Garmin GPSMAP 76CSx PKG incl USB PC Interface cable 010-00469-00 $369.95
In the past the 76CSx has cost more money but the price is down. I believe the 60CSx has a nicer looking case, and it looks like a radio because the antenna sticks out. The 76CSx has the same antenna, but it is protected by the case and floatation . I like the way I can hold the 76 series in one hand and push the buttons with my thumb.
When the price is the same I believe the touch and feel of the unit becomes the determining factor. And the answer comes down to the user. I would go to a retail outlet and handle the product.
I would buy the 76CSx because I have a couple of boats and enjoy being out on the water. When I was using my old Garmin Legend I was always concerned that I would lose it in a few hundred feet of water. (1)The fact the 76 series float is important to me. At times a fishing partner is handling my gps, and if it gets dropped over board I can get it in a net. (2) And the ability to operate it with one hand is important. (3) Over the years I have taken a couple real hard falls out hunting, in fact I have damaged two scopes because of falls. I believe the 76 series is a little more Old Fool Proof.
Scary, having written it, let me say that the 60CSx is a very good unit and it comes down to personel preference.