If you ever wanted to give Heroes of the Storm a try, now would be the best time to do so as Blizzard has made all of the characters free to play. The promotion will only last until 10am PST on January 16th, so make sure to jump in as soon as possible, or else you might not have enough time to give all of the heroes a proper try.
And if you haven't been paying attention to Heroes of the Storm this past year and are now wondering what in the world has even changed, you'll be glad to hear that Blizzard has posted a brief video summarizing all of the recent additions. Have a look:
As for whether you'll enjoy Heroes of the Storm more than Dota 2 or LoL, that will depend purely on what you hope to find. If you're looking for a hardcore game that will take your years to truly master you're probably going to be left disappointed, but if you're looking for something you can enjoy without too much of a commitment, then you might just find what you seek. Either way its well worth a shot, and with all of the heroes now freely available it really is the best time to dive in and see if its your thing or not. Have fun!