Measuring 150kHz, ~30V peak waveform with good resolution
I used an AM685 comparator, decades ago, to implement a tracking ADC to measure the pulse-flatness of a 120 MHz data stream needed for FM modulation of a transmitter.

The AM685 has a LATCH_ENABLE pin, thus you can control when the decision is made.

Decades later, National Semiconductor was using this same approach for pulse characterization in their production lines.

The AM685 has about 6 nanoseconds tpd, used only NPN transistors, and Zener diodes for level shifting between stages; the latch-dispersion-time is about 400 pico_seconds, thus you can perform a "track" at points within 1 nanosecond of sharp edge, with confidence.