I'm not seeing browser improvements, either - and (as pointed out upthread) a way to test that is to put your car on good Wi-Fi. If the browser doesn't improve when on Wi-Fi, 3G vs. LTE isn't going to help you. My experience is that the browser just sucks rocks regardless of whether there's 1 Gbps to the car or 1 Mbps to the car.
This matches my experience. LTE helps google maps redraws quite a bit, and slacker but to a lessor amount. The browser just sucks.