Find someone you know with your wireless provider who has a LTE device invite them over and look at their phone. Probably the most accurate way to know, what you might be able to expect.
3G and LTE operate on different frequencies and because of that different wattages. They are also generally different ways of processing data wirelessly. All of that plus 100 other aspects that can affect wireless signals.
I live in the middle of San Diego, which ATT as covered rather well there is about a 4 block area in my neighborhood in side of which I live that ATT can go from full bars to 'No Service' in the blink of an eye. My neighbors and I who had ATT complained so much they sent out techs to our area to measure signal strengths and such, never did fix it and most of us switched to Verizon after a couple of years and going through those stupid Micro Cells they tried to give us and say it was fixed. My roommate still has ATT and still has the same problem, every other company (VZ, TMobile, Sprint) perfect coverage...
Short Version: there is no way to know until you do!