I know people may say, keep both map. But what you want, update and follow the dota2 game, new map, balanced skill, item recipes changes, new hero even there? Or you want to sit back and stay forever on the old version? You know, you can always host game you want with entbot. So host the older version and autohost the new map (
when everything is fixed). Please, read the underlined things. I know for people who got frame drop and etc it was ugly.
I didn't played the game (on wc3) but I must know what it had feels like (all the changes). If you mind, we had all the same problems (even bigger) in dota2 when this came out. Give it a chance, tho. When lag issues will be fixed, it will just be a matter of time to love the new map pathing, hero balance and others.
I hated the new map for 10 game or so. Pathing being new, when I was arrowing 'anticipating' the other hero movement (based on old map in my head), I was raging, since I was arrowing in nowhere... Wasting my arrow/mana/time xD
This game have is up and down since beginning. Just give it time for dota1 to be up