I got 2 digital ones at radio shack about 10 years ago.. Both still working. I've been waiting for the batteries to die... but they are still going.
one is always 1.5# higher than normal (for normal tire pressures 30-45lb)
the other is about ++ .5# to correct
I got 2 cheapie digitals both were trash and inconsistent.
and a stick thats about 30 years old thats within 2-3lb
My GF has went through about 5 pieces of trash ie 99cent pencil style..
none were very good
2011 Subaru Forester X Prem. 5MT