I have a boofy hard mouthed QH gelding that I've owned for just over four years. He's always had pretty terrible brakes and despite many hours of fine tuning them (and some pretty fabulous improvements) he's still quite slow to stop. After discovering his stop became almost flawless when ridden in a halter I purchased his first sidepull this year and despite keeping my hands soft and getting him one of those wonderful fluffy nose bands I still found him getting rubbed.
Only the other week I found another hackamore and purchased it. Turns out it is one of those mechanical hackamore's. I didn't even realize at the time. My horse is currently spelling at the moment so I haven't had any real chance to trial him in it apart from a quick ride down the road but he's already showing such potential in it. He is much happier without a bit!
My question to you is what do you think of a mechanical hackamore? The below photo of a hackamore similar to the one I purchased. Mine has a wider, padded noseband which is what made it appealing to me. It spreads the pressure out and shouldn't cut into his nose quite like the sidepull pictured below.