Yes, burst radars are very common these days and won't show up unless someone ahead of you gets lit up, but guess what? Unless you're alone on the freeway, there's a pretty solid chance someone ahead of you is gonna get lit up before you do and it will give you a warning to slow down.
I drove with a V1 for years and it saved me from many, many tickets. (I didn't get a single one the entire time I owned one.)
My point being; radar detectors are useful tools. It can be a worthwhile investment if you buy a good one and know how to make use of it.
(For anyone wondering, I sold my V1 to a friend when I decided the german sports car phase of my life was over.)