Many AOE2 players didn't mind switching to AOE3. Most of these people were the ones leftover from the AOE2 --> AOM switch. A lot of AOE2 players didn't want to go to AOM, it was just too different from what they were used to.
It really depends on how into AOE2 you are, how long have you been playing? If it has been for awhile, you might not like the change.
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I downloaded the full version awhile ago (I think it was like 4 days before the release), and didn't care too much for it. The demo didn't seem to let you do enough to make an informed decision.
AOE3 already has a huge DM player base, so if you plan to play it online, you'll be able to keep yourself busy. The AOE2 game is just about dead, all of the cheaters finally killed it, despite players making their own patches.
AOE3 on the other hand, will have very few cheats/hacks. The way ESO works is very hard to mess with, and there has only been one hacker who created/sold something that worked with ESO, who now has stopped.