I have the model like yours but without the voice sh*t. It works really well, the only thing you need to worry about are the "instant On" radar guns the cops use. I get hit by those 2-3 times a week and when i hear the KA band beep with one bar i slow down.
Also i almost got nailed in my town the other day. our roads are dirt through the residential areas and the town put up speed limit signs of 15 mph for dust control. Annoying as hell to go down this road 15mph UGGG. well a few weeks later i just left my house and im going to work and my X band is beeping, nothing unusual false alarms all the time on that band. well all of a sudden it gets stronger which was odd so i slow down from 24 to 20 and sure enough i see the front end of a county sheriff cruiser poking out from bushes. now i hit the breaks and get it down to 15 before he locks me in.
Until then i have never seen a cop use the X band, but now when it goes off it makes me jump.
another is Laser. If you get tagged by a laser sure your radar will go off but its too late, your speed is already locked on his gun. The only way to defeat laser is to pick it up when the cop nails the car infront of you and you pick up the signal.