Probably not a bad one amongst them. The only issue is price, coverage and the currentness of them. ( is currentness a word ? )
I use a Blue chart, but I am reliably told the Navionics are better... not told reason, but could be more current and more definition ? Don't know about accuracy !
In the end, if you are looking to purchase, you'll need to start with your budget, from there you can wittle away at the ones that come within that range.
Phill