Technology marches on...
Navico still sells the 3g and 4g
radar, but the newest and coolest is the Halo. Also based on "broadband" technology, it's not marketed as such anymore because everybody has it, so it's not really a distinguishing feature. The Halo has all of the advantages of the 3/4G and lots more too.
If you are upgrading and can afford it, the Halo is clearly a step up.