Endermen don't use their teleporting ability.

I did 3 tests in 1.7.2 and 1.8.7 in survival mode.

First test: Just hitting endermen
1.7.2: Endermen teleport around and sometimes teleport behind you etc and avoid damage. Works as intended.

1.8.7: Endermen just run towards you and you can just punch them against a wall and they won't do anything. Bugged.

Second test: Making 3 block high walls and aggroing endermen.

1.7.2: Endermen teleport inside the walls to attack you. Works as intended.

1.8.7: Endermen run against the wall without doing anything. Sometimes they lose interest and return neutral. Bugged.

Third test: Staring at endermen.

1.7.2: Endermen freeze and do the enderman growl noise, then teleport to attack you. Works as intended.

1.8.7: Sometimes they won't do anything if you look at them. When it works they just start running towards you straight away. Bugged.