The single most important thing I miss in LTspice is the ability to plot things of multiple runs on top of each other. Cadence Virtuoso calls that "Append Plot".
What I mean: I want to plot one node of my circuit, hit "Run" and plot. Then change the topology and run again and plot the result on top of the first one. This makes it easy to see the impact of multiple blocks/parsitics/changes directly in the waveform.
I know I can export the plot after each run and plot them on top in MATLAB for example. I also know I can use
.step. But this does not (easily) allow for topology changes. None of these two are solutions.