Well with the Flyers only having AV 10 and no defensive abilities other than Jink they will not last long on the battlefield.
Only takes two glances and goodbye flyer.
"But the Wraith Knight is why people get into Eldar now."
Costing more than a Land Raider will doom it from most Eldar player lists.
Plus if you got a hit against anything you do not reroll it trying to get a six. Because you are far more likely to roll a miss than a six.
Remember Eldar are like High Elves high unit cost and there is just so many points that you can use.
Also the Hemlock ability also works against your units.
Units that you will see are:
Warp Spiders
Crimson Hunter (though the Eldar have better flyers from FW)
Vyper Squadron
Units that you might see:
Swooping Hawks (until players find out that you will not be able to land the anywhere near the enemy)
Hemlock (until players learn that it is not that good)
Unit that you rarely see:
Shining Spears because there are better choices.
But the go to unit for Fast Attack will be:
Warp Spiders because they are Fast and can bring the pain.