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)

have been using minerstat for about 9 months as a newbie to mining and must say it has been very easy with no real issues. Have tried mining various cryptos and once you know the way around its all quite easy.

Good control site, much easier to set up and control then hiveOS. Also has many more options. Unless you have multiple rigs, i cant actually sugest you get the paid upgrade, its not worth it. good for multiple rigs though obviously to have them all in one place.