Easy to use
Some corrosion issues on the metal mount, back cover; screen can shatter; display may be hard to read in direct sunlight
I waited until this unit went on sale at West Marine and it turned out to be a timely, good purchase. They discontinued the 400c shortly after and as far as I know, this was/is one of the few Garmin handhelds that came/comes with the bluecharts installed.
Little did I know how useful this feature would be, and it is not so much the chart displays, but rather the tide stations and calculations that I find invaluable for kayaking. With this feature, you can select the nearest tide station on the map and get the highs/lows for any day you wish...(the current day comes up by default).
As far as other displays, I downloaded free topos and road maps, so I have been able to use this GPS for trails and for driving directions. It really can do it all (it's just not as good as a dedicated vehicle GPS), so I feel it has been a great value. I know that most people now just use their phones, but believe me, you do not want to use your phone for navigation while kayaking, unless you have a waterproof case. Also, phone GPS features may not work if you don't have a signal. In the middle of the Everglades, there is no phone service. This GPS always works, as long as you have batteries.
The Oregon series is waterproof to a few feet but it does not float. I always keep mine on a retractable lanyard when kayaking. Also, I have had some corrosion issues with the metal parts on the back cover. Fellow paddlers have had the same issue. I contacted Garmin while the unit was still under warranty and they sent me a replacement cover for free. I am still using the original cover until such a time that it definitely needs to be replaced. I make sure to rinse the saltwater off after each day of use but it still takes its toll.
Battery life is pretty good..I turn the GPS on and off throughout the day, so I don't burn through the batteries. I still rely on traditional navigation methods for the most part (compass and charts), but I have to give the GPS some credit for getting me out of a bad situation once or twice.
The most useful skill/trick I find is being able to touch any location on the display and get a range and bearing...with that info, you can just follow your compass to end up exactly where you want to be. That coupled with the tide features make this a very useful tool for me.
In the spring of 2013, I somehow managed to shatter the display screen. I had the unit in a bag with some other stuff and apparently it took a good hit. I paid around $110 to replace the unit with a refurbished one, which is working well.
For my intended uses, it is still important to have a waterproof unit as well as one that does not rely on cell phone service. Still, with smartphones advancing they way they are, many users will simply find it better to go that route. The antiquated touch-screen features of this unit leave much to be desired when compared to modern touchscreens. However, the touchscreen will still work when there is water on the screen.