I have run a radar detector in the distant past, (Valentine One), and stopped using them in '10 after the MERA 10-n-10 rally. I'm not generally a big speeder, typically running 5-10 over day to day on highway/interstate. (I also have run high speeds all day in the past for various reasons.) I don't speed into/thru towns. I used to live in OR and UT for 50+ years, so wide open Western US is very familiar to me. 99% of the time you just need to pay attention and use common sense. Don't exit a small town and wick it up to triple digits, especially Eastern OR/WA and NV, because it's common for a LEO to be parked a few miles out of town waiting for that behavior. Co Sheriff loves to park at the intersection of a couple of rural hwys and point his radar down the road too.
I used to get hits on the V-1 way out of a town I was heading towards too. Local LEO is parked in town running always on. That's sort of good info to know, but really also moot if you're not an asshat and come into town at the speed limit. Show some respect for small towns and cities and you won't get tickets there.
With instant on and LIDAR there is a selection process for the LEO. If you're not being targeted, yes, sometimes you pick up splash from someone else being targeted and get some warning that that's in the area. Less so with LIDAR, but because it's line of sight, you should be seeing them before they see you unless you came over a hill or around a blind corner hot, in which case you should be prepared to get the ticket. No detector will save you against the LEO parked just over the hill aiming back up, regardless of what device they are using.