Pointed Discussion

Whats better: lowering the mana curve for versatility(ex. this card), or keeping the mana curve for inflexible mana (ex. Boros Garrison)? Discuss.

The good thing about the lair lands is that you don't lose tempo on the turn they come into play because you can float mana of the land you return to your hand. The downside is that you "lost" a land drop for all subsequent turns.
In most cases the tri-lands from Shards of Alara are better (you abandon one mana the turn you play them instead of a land which comes into play untapped) but the lairs still have their uses like bouncing cycle lands, Gemstone Mine or Llanowar Reborn etc. later in the game.
The bouncelands from Ravnica block help you to hit your land drop each round, give you the possible bouncing benefit of a lair land but involve the risk of getting sort of two-for-oned if they get bounced or destroyed. Early on they can hinder your development and force you to discard down to seven.
I think Zendikar with its new keyword Landfall will strongly promote the reevaluation of all bouncelands (a bounceland like Dimir Aqueduct gives you guaranteed land drop each turn, that is if you bounce itself back each time you play it).

I have 5 of these and 5 of the Zendikar triple lands in my Sliver EDH deck. I originally only had one lair as a spot holder for a Zendikar triple, but after playing with them I realized that they were actually pretty playable. Most of the time I just waited until they were the last land in my hand to cast them anyway, so it didn't really make a difference unless I happened to draw a land next turn. I think they are pretty underrated and I am surprised they don't pop up in more EDH decks, to be honest.

Landfall and lands with comes-into-play effects combo with all the Lairs, and they are additional mana fixers in EDH.

you dont need to return an untapped land, and it doesnt enter untapped. really cool. 3.5/5.

Why didn't they have any Lairwalk or "search for a lair" or has x if you have a lair?

Here's my continuing saga of multilands in Magic, which I started in Castle Sengir.

So, after this colorfest the multilands (including lands that not necessarily produce multiple colors of mana but help otherways to diversify mana production) to follow were:

Seventh edition: City of Brass and Ice Age painlands (Adarkar Wastes etc.)
Apocalypse: Enemy color painlands (Battlefield Forge etc.).
Odyssey: Crystal Quarry, Deserted Temple, Tarnished Citadel, mono color lands that could sac for any color (Abandoned Outpost etc.) and allied color filter lands (Darkwater Catacombs etc.)
Torment: Tainted lands (Tainted Field etc.)
Judgment: Krosan Verge and Riftstone Portal.
Onslaught: Grand Coliseum and allied color fetchlands (Bloodstained Mire etc.)
Legions: No lands.
Scourge: No color producing lands.
Eight editon: City of Brass and Invasion comes in tapped allied color lands (Coastal Tower etc.)
Mirrodin: Glimmervoid.
Darksteel: Mirrodin's Core.
Fifth Dawn: No lands.
Champions of Kamigawa: Forbidden Orchard and allied color taplands (Cloudcrest Lake etc.)
Betrayers of Kamigawa : Tendo Ice Bridge.
Saviors of Kamigawa: No multilands.
Ninth edition: Ice Age and Apocalypse painlands (Adarkar Wastes and Battlefield Forge etc.)
Ravnica: City of Guilds : , , and versions of pay life or comes in tapped dual lands (Overgrown Tomb etc.) and comes in tapped two mana lands (Boros Garrison etc.)
Guildpact: , and versions of pay life or comes in tapped dual lands (Godless Shrine etc.) and comes in tapped two mana lands (Gruul Turf etc.)
Dissension: Pillar of the Paruns and , and versions of pay life or comes in tapped dual lands (Blood Crypt etc.) and comes in tapped two mana lands (Azorius Chancery etc.)

Ok, that's the second colorfest with new dual lands. Dual lands being lands that are two basic lands at the same time and thus fetchable with something like Bloodstained Mire and affected by something like Boil.

I continue this series in Pillar of the Paruns.