Consumer Reports did a comparison about 8 years ago, and found that pen
type gauges can be accurate but frequently aren't unless you buy the
"right" brand. I did, but now wish I'd bought a handful. No doubt the
AutoZone gauge they recommended has gone through a few changes. (There
were actually two AutoZones tested -- one model was excellent, the
other sucked.)

The dial types are very accurate, typically. Until the first time it
gets dropped. Then all bets are off.

If you're rough with gauges, or have some extra bucks to spend, I'd
wager on the piezo electronics to be pretty accurate in general.