very usefull when you want to keep an eye on your rig while away from it, you can even restart it, overclock, undervolt, check temps, and musch more while using the free edition. Honestly, i couldn't ask of anything more (except for a few things, but they are covered by the paid version)

Great software and service for peace of mind. A broad offering covering all your needs.
Courteous and knowledgable help when you need it and a friendly user community that pitches in.
Easy setup for beginners and flexible for more advanced users.

Took a moment to get used to but the support staff is solid with a quick response time and theyll help you get your mining gear on track if you ever get stuck on something. From there its pretty straight forward, informative dashboard, every feature you can think of and tutorials on how to use them. not to mention the competitive pricing. you really cant go wrong with minerstat