I used to use a gauge long ago, I think it was an Accu-Rite or something like that, it was digital and measured to the 1/2 psi. It didn't lose any pressure either. In any case, I stopped using it when I realized that level of resolution really wasn't necessary, and the gauge broke when using it on car tires
. I also realized that the gauge on my Silca floor pump is "good enough" and a quick squeeze of the tire is adequate to get a good feel for how much pressure was adequate.
To keep the spirit of this thread morphing into something else, in my younger days I ran 700x23 and 25 tires (usually Vredesteins) pumped to ~120psi, I weighed between 200 and 220 lbs back then. Now I'm an old man in the mid-250's, run Continental Grand Prix 25 mm tires (measure 26mm wide on my rims) at between 90-100 psi on my Silca pump's gauge. Great ride and no pinch flats (I ride on pretty decent roads). I've gone higher than this and don't like the handling of the bike.