It is nice to have a wider speed range to play with and I used it to find the sweet spot that worked best with the sea conditions. Fun stuff.
You pointed out something so often overlooked. We talk about speed to get places quicker and speed to avoid bad weather, but being able to match speed to sea conditions for the best ride is seldom mentioned. Matching speed to wave distance and period entering and exiting inlets and crossing bars is an advantage too. I remember when we were being trained and our introduction to rougher seas as part of that. Instinct, due to our lack of experience, was that slower was called for and better. We quickly were introduced to matching our speed with the waves, with the period and distance between waves.