Dota 2 is ALMOST better than Dota. It just has to have all of the original heroes transferred over from Dota for it to truly be its successor.
I haven't played Dota in years too; I use to play LoL, but it got waaaaaaaay too boring. The fact that you have to buy, or grind, for the hero that you want to play is absolutely ridiculous.
The meta has changed significantly since 5.7 (when I last played Dota). With recent additions in 6.77, more and more heroes that weren't played at the competitive level are being picked. For example: Naix, Nyx (Nerubian Assassin), Gryrocopter, and Batrider have started getting first-round bans.
It all makes for a much more interesting game. One that won't go away for a very long time.