Navionics discrepancies

I wonder if you have found the Navionics topo maps accurate. 
I intend to buy the app this year but am not sure the online maps are accurate. 
I have covered willard pretty good but not happy with them. I have also looked at jordanelle and deer creek. And do not see the same on my Garmin finder.  I looked at starvation one day and was happy with the online map it matched my finder good.
What’s your experience?