My tire slips on the small loose rocks and deflects on slightly larger rocks while climbing at high pressure. I dont like it.
I run 25psi in the front and 28psi in the rear on my 6"x6" all mountain trail bike thingy, and about the same on my XC 29'er hard tail. Almost always.
I might add a couple psi if the trail gets especially rough, but only to prevent rim damage.
Generally speaking, floor pumps arent very accurate for long. Floor pumps tend to be tossed around a bit and air pressure gauges are precision instruments. My floor pumps never last more than 2 or 3 years. Plenty to get your moneys worth in my opinion.
Its good to have a spare gauge that is tucked away in a safe place to refer to, but how do you know THAT is accurate? I have the luxury of working at a bike shop and having so many damn floor pumps around me that Ill know pretty quick if my personal floor pump is losing accuracy.
I suggest you just compare your pressure readings to any other pressure reading you can find. Go to a bike shop and ask to compare pressure readings to confirm that your pump is accurate. They should understand your concern.
As long as you are withing 2 psi of the average that you discover checking other pressure gauges, Id say youre floor pump is just fine.