DotA 2 Item: Hand of Midas

how good is this item? And what would it be best to use this on?

IT's not used that often except by jungles some times mostly chen but still I almost never use it

This ITEM IS GREAT - Is a must for any hard carry. Only aim to buy this item if you can successfully farm it in 8 minutes.
popular on jungle heroes and hard carries
Naix, Furion, Enigma, - these junglers (mainly naix furion)
Void, Doom, mortred, spec, and pretty much any lane carry than can farm it in 8 minutes.

you need to use it 10x to get your money back (in theory) which on 100 sec cd is 17 minutes approx. around the 30 minute mark and above you will need to free up a slot, and will most probably sell it - which is why you need to farm in before 8 minutes. the bonus exp will make it more than worth while, you will then level faster.

Once I saw a Nature's Prophet pick up this item, along with his Shadow Shaman lane partner. They were leveled and farmed faster than the mid lane.

Be sure to buy two of these on Lone Druid