It's really irritating and BMW started this annoying habit sometime in 2007. My mom's 2006 325i has a soft but still linear throttle response; when I drove a 2009 loaner xi it was as everyone has described: nothing for the first 2mm of travel and then whoosh all at once. I adapted to it over time but there were still times where I'd go "oh whoops, sorry"

The newer automatic gearboxes don't help the situation. They're programmed to minimise fuel consumption so downshifts are lazy and shifts generally occur at haphazard times if you're used to the older GM-5 gearbox.