Not just titans. I play Imperial Guard opponents frequently and there is nothing quite as satisfying as having the Storm Serpent - Shining Spear one-two punch to obliterate a Leman Russ formation.

Storm Serpent doubles and lays a BM on a LR formation within 30cm.
Retain... Assault with Shining Spears, eight strong, plus two exarchs.

Leman Russ have lousy close combat values, which means they will have 2x FF4+, 1x FF5+ (token Hydra), 6x CC6+, 1 MW6+ for the Commissar who will inevitably be in there somewhere. That's 2.5 hits. Their awesome armor is halved because of the lance shots from the Shining Spears, so now they are running with 4+ armor straight up.

Shining Spears come in with 4+ armor, equal to the Leman Russ, 8x CC4+, plus an extra 2 hits a 4+ which means they will take out an average of 2.5 Russes.

Eldar...
+2 for BM advantage.
+1 for Inspiring Advantage (assuming all characters survived on both sides of the assault)
-1 for outnumbered (and half the time you'll have equalized the numbers)

So you go +2 into an assault roll against arguably the toughest formation in the game after reducing their numbers by a quarter. And God help the LR player if you've managed to kill just one tank prior to the attack, as that puts you at a +3 or +4 going into the assault roll.

If you lose, you lose small and withdraw 70cm to safety.
If you win you win big, breaking (most likely) the enemy's BTS, costing him at least one more unit, setting it up for a severe pounding while broken, and you still withdraw 35cm to fight another day.

Shining Spears also FF at 5+, which make them perfect for clipping assaults.

Alaitoc is just as, if not more, flexible as Biel-Tan, and it has no special rules or formations (unless you insist on counting aspect troupes and ranger hosts as special formations simply because Biel-tan flips it).

Alaitoc lacks the punch of a full Aspect host, and is therefore likely harder to use, but for me I'd say the aspect troupe is more flexible than a full host, not less.

Your second paragraph sums up why I feel that the Biel-Tan list trumps the Alaitoc list for a beginner.

I originally had painted some of my models in the Alaitoc colour scheme for SM2, but after examining the NetEA Alaitoc list, I decided that it wasn't for me, on the basis that not having access to full Aspect Hosts didn't suit my style of play.

I would count troupes and hosts as special formations because they are the opposite of Biel-Tan.

What you are saying is that Biel-tan is the default list because Biel-tan is the default list. Seriously.

As somebody who started out with Warhammer 40k in the 2nd edition, what really bugs me about Alaitoc is that they have an Autarch as their supreme commander and not a Farseer.

I still agree that Biel-tan is more newb-friendly.

Since this thread concerns a newish player I will remind people that the color of your minis has nothing to do with choice of list you're taking. However I had mad respect for anyone like Irisado who strives to keep their colors and lists matching, it has no bearing on the game. My Minotaurs show up as Blood Angels and Iron Hands all the time

carry on

What you are saying is that Biel-tan is the default list because Biel-tan is the default list. Seriously.

It can be the default list because it's the first one to be official and the only one in a print book, but nothing in the list itself makes it more "default" or "basic" than other lists. The Aspect Host perfectly encapsulates Biel-tan - a big reliance on aspects which just isn't present in any other Eldar army. They're elites, not the backbone (that's guardians).

As somebody who started out with Warhammer 40k in the 2nd edition, what really bugs me about Alaitoc is that they have an Autarch as their supreme commander and not a Farseer.

I still agree that Biel-tan is more newb-friendly.

Regarding second edition 40K, what you have to remember is that there was no Autarch back then, so trying to compare it to the EA lists as a result is a bit of a moot point.

I think I know which army Matt will pick - Ulthwe - the one with the highest SR.
That Give's Matt the best chance to influence the game.
As most units are the same, the higher SR will give Matt the battlefield control he likes.
I kinda hope I'm wrong though...