Me neither. Mine is reasonable most of the time (something between 0-100%, and I just got a feel for when it was likely "dry" enough to need watering based on my usual schedule and the rainfall amounts my area was estimated to receive, plus how long it stayed at that level), but as of a few weeks ago, mine is now giving impossible values:
I'll probably put it away for the season soon and try a reset and re-pair next spring, and hopefully it will be better then. I had similar problems at some point last year. While it was fun to experiment with, I'm not sure I'd really recommend this device (it also does temperature, but that's not a good indicator of outdoor temperature for me given that it often receives direct sunlight, and I'm assuming it's temperature of the upper part and not the soil probe, though I don't know). Hopefully it works better within Spruce's own system, but with my experience so far, I'm not about to find out. 
