I like this watch a lot but not giving it 5 stars for a couple of shortcomings. First, it's pretty accurate as far as the barometer (altitude) and temperature. The temperature is accurate ONLY when the watch is off your wrist, which the manual does state. My watch is reading 83.6 degrees as I sit in an air conditioned office. The compass is a little flakey, I tried to calibrate it for about 10 minutes and it never really completed calibration, the watch just gave up. It seems to be off by about 10 degrees so I'm going to have to work on fixing that. As others have said, it is very difficult to read it indoors but it is very readable outside in the bright sun and the numbers (for the time) are very big. The manual leaves something to be desired, it could go into more depth about how and why things are the way they are. For example, if you set your altitude to a known height, that alone should set the barometric pressure, but it doesn't, that is another step and when you do that, it changes the altitude! I've managed to get them both in synch and they're pretty accurate now. The watch face isn't too big as some of the triple sensor watches seem to be and, on top of that, it's a really nice looking watch. I feel for a watch under $50 it is well worth it and I would definitely buy it again.