Whilst I get how that (speed) might be of importance to anyone doing it for a living, in many cases (especially where care, accuracy and 'feel' might be important to the outcome), I would generally use a hand driver.
I used the ID yesterday because 1) those things weren't so important (daughter had stated she didn't GAF about the 'look', as long as it worked and was safe (and she knew even my worst efforts would be)), so if a few screws had been over-driven (not flush with the surface), that wouldn't matter and 2), if I had slipped, there was no aesthetic surface to damage (I had used the lengths of CLS she'd collected to best effect, knotless bits for the crossmembers, damaged corners on the back of the legs etc) and 3) we wanted to get it done before it started raining or got dark.
We dropped it off outside her flat and she took it in and assembled it. I offered her the ID but she said she preferred to do it by hand (again, for the control) so left her to it. We ended up going back up there later because she couldn't find a decent PZ2 and was worried she would damage the dead of the screws using a PH driver she had and it was taking quite a bit of effort (mostly because of the poor fit of the driver etc). I left her the ID and she tried it but was too noisy for the flats at that time of night. After a couple of questions (and help from the clamps I also left her on the second visit), she got it all together and it fits in the space like a glove (it actually looks like it's 'fitted', not free standing). A couple of rubber wedges should take out any safety slack I put in there and without making any holes in the property.
Sure.
I generally wear some ear defenders when doing anything that is very loud (and always have) ... or loud over a prolonged period (like I used them when cutting up the timber with the bench saw). But because I was doing the assembly in bursts (clamp, drill, countersink, two screws, rinse-repeat) and was outside, I didn't think it would be needed. Next time I think I will though.
Well, if hammering the nail with a riveting gun ... ;-)
Cheers, T i m