The reception is pretty great on the Atrix.
When I first got a phone with Bell, I got the HTC Desire Z, and the reception was atrocious. I could barely go on the main floor of my home without losing signal completely. Or if the phone was in my pocket on the second floor, it would lose signal.
However this wasn't the case with the Atrix, it pretty well has 4/5 bars throughout my town, whether I'm on the main floor of my house or the second floor, or even the basement for that matter. On top of that, the phone is just excellent. My brother owns the Samsung Galaxy S, and it is a horrible phone in comparison. Between speed, battery life, and signal, the Atrix out shines it in every aspect.
Hope that gives you a better idea.