I played Heroes of the Storm during beta after having played League of Legends, Dota 2, and some of the original Dota. My playing experience with HotS during the beta was good, but being a veteran of MOBAs there was much lacking for my tastes personally and I became bored. Here's my pros and cons.
Pros:
1. Some fun characters and Blizzard's great variety of characters. I loved Tyrael's kit in the game. Easily my favorite.
2. Map variation. I think it has a great map rotation which keeps it from getting stale as far as the playing ground goes. The different objectives for each map also provide a nice variety.
3. Easy to get into and put down. This game is noob friendly for the most part and the games don't last very long so if you wanted to get a quick one in, you can without whining for a surrender if you need to leave. Hint: Never play a MOBA if you don't intend to finish the game.
Cons:
1 . The grind/pay system. After Hearthstone's P2W scam/scheme I was pretty disappointed in their MOBA scheme. The grind during Beta was retarded to unlock locked champs...the skins are just about as bad as what Mortal Kombat X charges for their characters/skins...but what's even worse is that the skins just aren't very good. The heroes cost way too much to unlock for the system.
2. The level system. Team leveling for a MOBA is stupid. There's nothing else I can say about it. Its just a dumb dumb dumb mechanic. Why even have levels if its going to be a team level system? At least with the other popular Mobas you have the opportunity for you or your teammate to make up for someone who is dead weight. In this game, the dead weight either doesn't matter or matters so much it kills any chance your team would have. This needs to be revamped from scratch imo.
3. The lack of real strategic gameplay. Having the clear objectives pop up for advantages is nice but there's not really any other strategic gameplay than zerg and counter zerg. With the other games you have so many champions that strategic gameplay matters. Team composition matters in games like Dota and LoL. In this game...not so much. Just get good with one of the few champs and go zerg. It is too much like Starcraft 2 'strategy' which is pretty horrible imo.