I don't know if you are also thinking of the awful vibration that the new 737s cause at landing. I am flying the 400, 500 & 700. My theory is that the new 737s are like shopping carts; The wheels are dragged behind and sometimes the wheels on the shopping carts vibrate alot because of this. The stall speed on the new 737s are a lot lower than Vref, compared to the 400 and 500. My experience of the 700 is that if you let it touch down at a lot lower speeds it lands smoothly. (Of course, don't fly it at lower than Vref speeds and don't cause a tail strike)
Happy landings