Well it's a bit of an odd one in the DotA-like genre. There are no carries, so a good player can't carry the team if his teammates are playing badly. However, it's much easier to master, imo, since items are not something to worry about. The inclusion of Talents does add customisation to how you spec your Hero, but it's not like with items where you have to worry about last hitting or not stealing kills from the carry or even pushing the lane too much.
Heroes have set roles, and while it is able to nudge them in a certain direction by picking specific Talents, you're still going to do largely what your class is meant to do. There is a laning phase in the early game, meant to give your team experience and maybe push the lane a bit, depending on the hero you use (for instance, you can snipe the enemy's fountain if you play as Tassadar early on, though it can be a risky maneuver). Spreading our the team early on is recommended to amass the most exp - just steamrolling in a deathball makes you miss out on useful exp and consequently gives the enemy team a level advantage.
The biggest flaw with HotS right now is the fact that, unless you have a co-ordinated team, you can get completely wrecked. Teamwork in HotS isn't just important, it's VITAL. No teamwork means you fail at map objectives and just plain lose teamfights... and as we all know, feeding is bad.
That being said, I love the game. I'm generally bad at Dota-likes, but HotS is refreshing in it's newb-friendliness. Now, if only I could get a stable team...