I've always just used overhand. I figure if the weight gets to a point where my grip becomes and issue, I need to strengthen my grip, not switch it. I've never used straps, but I have a friend who does. He actually starts with them, because he says if he doesn't, he won't be able to do his last sets. I think he is cheating, personally.
I agree. The only time I could see straps being justified if when you're lifting many times your body weight. I think I get sweaty hands easily, so the bar slips and I feel like each rep I need to set the weight down for a second and regrip..
Chalk is your friend!
i do the normal front overhand grip for deadlifts. i have to use straps when i start going heavier than 315lbs though. i don't use them for warmups but when i start doing working sets i use them. i use straps for shruggs as well, but again, it's when i go heavy. i shrug more than i deadlift.
it sucks in the winter time too because my hands are really dry and even with straps my dry ass hands still slip.
never used a hex bar and they have one at my gym. i have no interest in using it. the only people i really see using it are people who don't really know what they are doing. but with the hex bar you are holding at the sides as oppose to in front of you, so i'm sure it feels different. it seems like it would be easier because of that though because you can have more leg drive.