I've had trucks where a bunch of little elements conspired to make it hard starting. Older starter, older batteries, slightly off calibration sensors that still didn't throw any codes, real f'ing cold weather, etc. I've had to use ether on them. I'd only bother with the built in ether thing if I was needing it A LOT, and if you need it a lot, then you've probably got some more serious problems that should be fixed. Occasionally, just hose the screen on the intake down and then hustle back around and start the truck. Fresh batteries, some diesel additive, and synthetic oil go a long way to avoiding the need for ether. I like to keep some around just in case lights get left on or the liftgate drains the battery or whatever, as ether can make jumping it go a lot quicker. But it's definitely something to be avoided.