I have a Gloucester 20 with a 8 HP NS8B nissan and use both techniques depending on the "tightness" of the situation. I can leave it locked and tiller steer when the situation presents itself to have more room, but will lock the tiller and just use the OB if I need to turn on a dime. Everything has it's pros and cons and a pro to an OB IMO is that it can be turned with directional thrust, something a lot of people with fixed thrust don't have the luxury of. To me, there is no need to go one way or the other as an operating mantra.
I am well aware that the 8 hp OB I have is a bit over powered for my boat but I got a KILLER deal on it, 280 bucks, and its got the 25" super long shaft and a generator on all while weighing in around 60 pounds.
Anyhow, one of the reasons it was so cheap was the original tiller handle/throttle was missing. I built my own aluminum extension with shift and throttle controls at the far end. This lets me steer when needed and have my shift/throttle controls easily accesable when needed. To me it works far better than the standard OB twist throttle setups! I also probably have the only 8 HP OB in the world with a used 150 dollar sparco sports car shift knob for the gear selector! The clear straight acrylic lever is the throttle. Easy to feel which one you need and keep your eyes on the ball.