Have a max 360 (not the one with the wifi), using a blend mount and a mirror tap. The detector comes with a few years of the escort live subscription which was decent... not great, but after the 3 years (mine just ran out) it's like $50 per year for it + the defender database updates (which I'm often too lazy to do).
Not specific to the Expy, my Max360 does have a weird variance in reported speed of about 1.5mph from my actual speed. I figure I just need to send it in to get recalibrated, but I'm lazy.
Bottom line, is the Live App is only as good as the number of people utilizing it, if you live in an area that doesn't have a lot of people with the app on then it's not going to provide much advanced warning - and then placing it into a subscription model just ensures fewer people will utilize it.
The app also configures your device, but it's a little confusing, and doesn't do a very good job of explaining things, and sometimes, the settings would reset and I'd have to go back through them.