Garmin 3490lmt

I have a 3 or 4 year old 755t with life time maps. I'm thinking of getting a new 3490lmt. I work as a trucker and I've used and enjoyed my old 755t very much, but it is starting to act up on me.I have a new iphone 4 and if the blue tooth and text work with my phone i would buy it. does anyone have a new 3490lmt? do you like it? how well does the blue tooth work? can you hear it while driving?