The big stuff doesn't move around too much, that's what I figure.
But I am seeing some differences in chart detail between a 10 year old Garmin chip and the latest Blue chart app download. Mostly, new fractions of feet for some of the shoal areas(I appreciate that extra detail in my home waters).
Other than that, I like the clean simplicity of not too much data on the chart so far. I'll take a look at the new app you mention in the future. AC has to figure out how to make money somehow.