And here's my mark of dedication for those who haven't seen. It is since done with the Biel-Tan symbol colored in, but I haven't had time to get a pic yet.
As for your question, Mark, it's hard to say how to beat Eldar specifically, because every Eldar player plays their army differently. Like any army, you just have to find the weakness in that Eldar player's strategy. My army is heavy on defense and shooting. I favor Fire Dragons, Pathfinders, Fire Prisms, and Wraithlords. Since hand to hand combat is also needed. I love to take Banshees and Harlequins with farseers. Fortune and Doom FTW!
Another thing to take into consideration would be that you change your army depending on what army you're fighting against. I.e. I'd take Dark Reapers if I were fighting a heavy infantry space marine army. And as said before, all Eldar players play differently. Eldar are very flexible in play types. Some people like fast attack armies, others like shooty, defensive armies (like me) and others take a more aggressive approach.
Hope I aswered your questions, Mark.
Becky