Gonna chime in here; in my experience with the WLD (had a weekly game running it for a while on whim), it seems as though nothing really changes for the Tier system. Our party was a Half-Orc Warblade (Tiger Claw focused, TWF'd Kukris [Houserule made TWF actually worth it], using homebrew feat to apply warblade abilities to Wis instead of Int), a buffing and support focused Favored Soul, a Half-Elf Factotum (not super optimized; trapmonkey and combat support- ran a "shapeshifter" flavor and made heavy use of Alter Self et la.) and myself, playing a Transmuter with some etc (Planned for Master specialist, War Weaver, few others).
This group played very much like a normal party- prebuff from the favored soul, open the door, tank charges and lighter combat role moves in to flank while Arcane sets up control and divine runs support, occasional patch healing. Perhaps best off at our level (6) was the warblade; his encounter maneuvers were always relevant and always ready to go. As were the Factotum's similar encounter abilities, the two of them handled a few fights on their own due to difficult circumstances. However, in the end, the Favored Soul and Transmuter REALLY ran the show; without combat buffs, the melees went down like cake and didn't really do much to enemies. During a tough boss battle (don't remember what encounter), the Favored Soul went CoDzilla and smashed Tokyo in a method consistent with a buffing focused divine caster.
A lot of the changes that the WLD suggests aren't always relevant; the lack of teleportation/rope trick/summons seems like it was to prevent the abuses of such by both players and DMs. For every nerf to Tier 1s, there is an equal if not worse nerf to others- not being able to use some of the most broken spells doesn't really hurt T1s too much, where the Take 10/Take 20 rules hurt lower tiers a LOT more. That is to say, the mean power of each class is reduced roughly an equal amount by this. The same holds true for rest issues with the melee types- HP recovery and Ability Recovery from rest are important if you've been in melee. Even worse is the fact that when we did roll random encounters while resting, the Factotum or Warblade were usually on watch and took the first few rounds of combat without support and were set back much more. In the one instance that the Transmuter was caught with an encounter, they locked down with two control spells (Celerity) and woke the rest of the party up at their leisure.
All in all, WLD doesn't change the environment and class dynamic too much; it simply weakens everyone a bit. The game itself is certainly restricting, but that seems like it's not truly directed at any one class or any metagame construct such as Tiers.