It is different, I have not actually tried playing LoL on full graphics but it seemed much more cartoony to me, I dunno if it is better or not when maxed out. If you played the original DOTA, Dota 2 reminds me much more of that stylistically.
And I am not a Dota fanboy btw, I don't play it religiously or anything but I am a huge fan of the concept, I played AoS the DOTA precursor way back in the day. I just thought that in LoL you did not get access to all characters at first, and I don't like the idea that someone can spend money immediately to have an advantage. If they changed that, then by all means, it is just as good as Dota, just different.