I'm reading Victory in Europe 1945: the Last Offensive of WW II. Found a couple things of interest. The book so far is very detailed about US operations after the Bulge.
First, US troops began making many attacks at night. For some contested river crossings, when an early thaw saw the rivers in flood stage, some US commanders had a heavy smoke screen laid down at likely crossing points, drawing heavy German artillery fire. Meanwhile the actual crossings were made elsewhere, sans smoke. Some got across with scarcely a shot fired.
In one case, a badly shot-up Panzer division was called upon to counter-attack. Due to serious shortage of fuel and weight restrictions on bridges, the Panthers were left behind. Mk IVs went in. I note that most counterattacks seem made with Mk IVs. Heavier tanks show up when they are in defensive positions, the odd Tiger here and there.