I don't know about everyone else, but I have a hell of a time keeping air in my tires. I can take my truck to a shop to have the tires remounted and tell them to GLUE THE F**ING THINGS ON TO THE RIMS, and I get maybe a year before I'm topping them up every week or two. This is true of my aluminum summer rims and steel winter rims.
Of course, this means that I'm forced to keep an eye on the pressure (no TPMS on a 2004 GMC Canyon) and I've been through a number of tire pressure gauges that either broke or couldn't be trusted within 10 PSI (67 kPa). I'm not afraid to spend some money on a tool that lasts, but I hate spending money multiple times on crap that doesn't work.
Hmmmm..... That also makes me wonder if I should even bother, as my next vehicle is likely to have TPMS.
I'll also take any suggestions for portable 12V inflators that will run at 100% duty cycle for an indefinite period of time, and will outlast me. I've gone through perhaps three or four in the last 15 years and could have spent that money on a decent one.