The app definitely makes sense, has way more power to add layers, and I think will be the way we use GPS in the future, but it's not yet as reliable and usable as the GPS with chip is.
The offline cache works, but it's very hard to know what you do and don't have cached, and there are glitches like mine not showing land ownership when I zoom in.
I also cover WAY too much ground for it to be feasible to cache detailed layers of where I'll be ahead of time. I need the whole state, which the GPS chip provides.
Last year I used it in Wyoming where I knew I'd be in one part of one unit, so was able to cache detailed layers, and for that it worked well.
I will say the ability to look at aerial imagery while in the field is HUGE, but I'm pretty sure there's other apps that provide that for a much lower price.