As someone who has played DotA Allstars for many years, when I first tried out Dota 2, I didn't really like it. I thought the graphics were way too different from Warcraft III's and I found it difficult to clearly spot units due to the color scheme. As well, the new shop/item system felt overwhelming, and the lack of command buttons (e.g. "Attack", "Stop") seemed odd, among other things. My first impression of Dota 2 was not favorable, and I didn't play it for a while.

But, after some time, my friends started playing the game and I tagged along. I gradually got used to the changes made in Dota 2 and began enjoying the experience. I then came to appreciate what they had done with the game; the new shop/item system was more efficient, the new courier system was convenient, the overall layout was optimized and more aesthetically pleasant, etc. Perhaps best of all, playing this game with your friends is so much easier than it is for DotA Allstars.

If you have played DotA Allstars but not Dota 2, I suggest you give it a try. You'll probably end up altogether dropping the former for the latter, like I did.

If you have not played either game, then you could try Dota 2 anyway, as it is free to play. Be forewarned that this kind of game may not be for you. The learning curve is steep - for some, it may take quite a while just to be able to play decently. However, if you do manage to climb the curve, Dota 2 can be an enjoyable game.