Barometer readings are valuable when you note the trend.  Is the pressure rising or falling, and at what rate.  If the reading is dropping fast, you will notice the change visually (building overcast).  Sharp rises and drops will also be accompanied with wind - think barometric charts with the isobars very closely spaced.   If you'd enjoy this type of thing, it adds to the fun just as any other gadget.  Note the measurement and trends on the days you have exceptional fishing and I'd bet you would see a pattern.

-YB