I would say I've had very good success. I purchased my Moisture Meter at Home Hardware over the summer but lots on Amazon. Very inexpensive. Sometimes probing gently in a couple of spots will give you a better assessment of the moisture.
For me I've found it a valuable tool. I have found my Calathea Ornata prefers a lighter watering every 4 or 5 days and other plants prefer a heavier watering less often so it helps me give them what they need.
Other folks have a great sense of touch with their fingers, which I don't seem to have hehehe.
