Thank you, that is extremely helpful! I don't mind details and examples if you should feel so inclined and I'm sure others wouldn't mind either. Could you maybe describe which is harder vs elastic? Personally I prefer harder bits as i'm not using them in extremely high torque situations but I think it would be good for everyone to know so that they can decide based on their intended application. Also do you find that the ACR "teeth" for lack of a better word on their philips has merit over PB swiss's smooth philips?
Well, I met Max Baumann a few years back, and I don't think there's anybody out there who knows more about hex keys and screwdriver bits than he does!
He explained, for example, that nobody wants a bent hex key, so as you increase the torque, his deform elastically and return to the original shape, until you get to breaking point! At less then breaking torque, his last longer than any others! He's right too - I have hex keys by other makers that are bent, or the tips are worn, but not by PB! I think he uses the same logic with screwdriver bits!
I have a set of ball hex drivers that have seen probably 25 years of use in my hands, and were second hand when I got them! They show no wear..!
I have a complete (ish) set of hex bits that I use at base and throw in my go bag. Again, the oldest are probably 15 years old, have seen regular use, and apart from needing a polish a few years back have no wear!
I once had an assembly job that required me to do up a pair of button head screws. I had to use bell hex bits as I was working at an angle, and over about 300 screws broke a box of 10 wera 2.5 mm bits. I used just one PB Swiss on the remaining 700 or so screws!
With regard to Phillips bits, I have to say that I don't use them much as here in the U.K. they were pretty much ousted by Pozidriv in the early 70's! When I do, the ACR profile is definitely an advantage! Although not a domestic product, Zephyr bits are pretty much industry standard in the British aerospace industry!
I find that unless I'm are working with decent quality screws, both Phillips and Pozidriv can be tough on the drivers, so when working with mediocre screws I much prefer to use a bit driver with replaceable bits - usually PB for Pozi and Zephyr ACR for Phillips, though I have some Stainless Wera drivers in Pozidriv that also have a sort of ACR pattern, and they seem to lasting really well!
Sorry - that's not very conclusive for any brand really, just what I've found!