they are up-to-date and good for checking older charts, particularly near changeable inlets or regarding bridges. Anything more than 1 season old can have significant ATN changes.
Because they are reduced in size I find them very hard to read on a moving boat or in failing light; ink jet printers are a tiny bit fuzzy, and laser printers are black and white. Either way, don't get them wet.
There are some other simple, useful nav aids on-line; check the right side bar of my blog for a few I find useful. The Coast Pilot and good weather
links are good.