Medium-stiff boots (rated 7–8) are an excellent choice for advanced all-mountain and freeride riders who want responsive performance without going full race-mode. They deliver snappy power transfer from your legs to your edges, which really shines when you're carving hard, dropping into steep terrain, or riding through choppy snow at speed. You'll feel noticeably more locked in and stable than you would in a softer boot.
The trade-off is less ankle mobility, so park riding takes more effort. Butters, presses, and tweaked grabs won't come as naturally, and these boots feel less forgiving on landings. If you're only hitting the park occasionally, that's usually manageable—just know what you're giving up.
Think of medium-stiff as the sweet spot if you spend most of your time exploring the whole mountain and want precision and control as your priority, with enough give to keep you comfortable all day.