Take the dwarf tree for example and compare against the old system for one of the racial enhancements that was particularly valuable regardless of what class you played, spell defense.

On live, a level one dwarf can immediately take one rank for 1 AP; the second rank picks up for 2 AP at level four. But most critically, there is no requirement that I spend AP on other dwarf stuff!

On Lama, I can't pick up one rank of spell defense without spending at least 10 AP already. That implies a few negatives: I can't start this enhancement until at least level 3; I also can't acquire it without spending AP on enhancements that may be completely useless for the particular class/build I am working on. A 10 AP spend just to unlock this means I may have to take, for example, the first Axe/Pick enhancement (probably useless if I'm a caster), one rank of tactics (again, probably useless for casters, heck, it's kind of useless for most non monks now anyway), and some combination of ranks of Iron Stomach (potentially useful, but not vital), Stout (utterly useless for any build) or Armor Mastery (mostly useless with paltry +1 AC per rank).

In other words, I'm wasting a lot of AP for many kinds of builds in order to get value I previously had quick and inexpensive access to on Live.

How this should work:

Get rid of AP/Tier gating. Use the limited UI space you have to present a matrix of enhancement choices like you do now but rely only on Character Level and Prerequisite Feats or Enhancements to gate the more powerful selections. This would mean that *it doesn't matter where the enhancement is located in the UI* as long as I meet any other requirements - I could take spell defense rank one at level 1 again; I could also take the first rank of tactics at level one if desired, just like on Live (I can't right now on Lama). But I still couldn't jump right to Dwarf Fortress, because it has a prerequisite line that I must take first. And I couldn't jump right to the top dragonmark enhancement, because again it's got prerequisite enhancements as well as feat requirements.

I believe a change like this would help loosen up the constricted AP problem that is holding players back from finding motivating build combinations. It would boost build flexibility and still allow you to gate power. Currently the AP/Tier gating is forcing too much wasted allocation.