So the gist is that HoN is DotA.
There is a hero in HoN called the Legionnaire. He is Axe. He has a dot that dmages you until you kill a target. He has a taunt that gives him bonus armor. He spins when you hit him. His ultimate kills you under a certain hp. In fact all of his moves have the exact same cost, damage, and CDs as axe, with the exception being that he can spin every .5 seconds instead of every .6. The vast majority of the heroes in HoN you will recognize as DotA heroes. Some have a few minor tweaks that make sense for the character. Swiftblade (Yurnero) doesn't have healing ward, which seemed somewhat random on him. Instead he has a percent chance to counteract targets who hit him, which makes far more sense for his character.
Items are a direct transition as well. Butterfly is called Wingblade, etc.
If you already like DotA, then HoN will please you. IT does everything DotA did right, and takes out the limitations of the WC3 platform.