My first game ever against eldar was this afternoon. It started with a bang and i took a strong position and hunkered down firing on the on rushing eldar.
The game ended in a draw with the eldar holding 1 objective and my templars holding 1 and contesting another with the fire prism.

things to take into account-

1. Warlocks giving the unit a 5+ invunerable against marines is annoying when uually it would be instant death.

2. The move 6, fire move 6 back is very effective against units with big gun hat cant see you.

3. Dire avengers are over rated and need better saves or theyre a waste of points.

4. The eldar are very resilient in combat if beefed up by decent power weapons.

What do you personally think about the eldar?

(They all need better saves and stuff like that. The dire avengers are better then guardians because they have a better profile

Yes, that may be but guardians (in my veiw) are only really useful because they can sport starcannons and bright lances right in the middle of the squad, dire avengers cant.
In my veiw i see Dire Avengers as an assault troop, used as a transport system to get their (pretty cheesy) exarch into combat. Take 10 in a unit!!!

Yeah true, and the guardian sqaud has the advantage of being cheaper and having platforms.

They are the eldar version of stormboyz, deadly but fragile. Eldar need wave serpents so they can carry more than 6 without having to footsolg under heavy fire. Hint Hint GW.