I have several Legacy locomotives, these all have a max of 200 speed steps. I also have a number of locomotives that I converted to TMCC, the conversions have 100 speed steps except, the conversions done with the Mini-ll from Electric Railroad. I believe all factory TMCC locomotives have 100 speed steps.
Factory TMCC, including those equipped with Odyssey I speed control have 32 speed steps. The various aftermarket speed control options, ERR, TAS, K-Line, had various number of steps, 100, 128, 256, depending on the specific product. Legacy has 200 speed steps.