A lot of the time reconditioned tools are returns that haven't been used or scratched up on shipping a safe bet is to stick with high end tool brands
I purchase used handtools all the time but not powertools. If the previous owner of a hand plane or saw has miss used the tool the faults r easily honed or fixed..with a powertool its not always easy to see the problems and fixing them is even harder.
I buy used tools when ever possible and typically pay half the cost of a new one. Patience is the key to getting quality tools. Review the listings on Craigslist regularly and you will find some amazing bargains. Remember... that new tool you bought just last week for $$$$ is now used and worth only a fraction of what you paid for it. So, buy used and save.
I wouldn't have been able to get into woodworking if it wasn't for used power tools.
With some care and setup work, my used table saw passes the nickel vibration test and is accurate to 2 thousandths. The used jointer was the same - bunch of cleanup and calibration and it is dead on. Both continue to be completely reliable and cost a quarter of what new equipment would have been.
Yes, they can be great bargins and great values. But, you MUST do your homework and know what you are buying and what problems to look for BEFORE you buy. I've had great luck with a Delta dust collector, several planes and many hand tools. Probably got them for 35% of the cost of a new one and they work great.
I primarily look at reconditioned tools for those one-off; or low use, special need tools. That said, my purchases so far have worked well. I try to buy from places I frequent for other tools, so if there is a problem or I have questions they know me.