A have a whistler cruisader on the bike, fully integrated unit. Works well. Never been ticketed when Ive been using it - and I spend a lot of time at 150+, and the front wheel in the air.
I have a cobra for the car, a $99 jobby, havent really tested it as my partner finds it annoying all the beeping.
The key thing is to get a unit that can be programmed to turn off all bands apart from Ka, otherwise youll get alerts left right and center.