It all depends on the relative power level of what we're doing.
When the characters are starting at level one, pretty much any Level Adjustment or Monstrous Race is going to be unbalanced.
Once we're up to say 7th level...
A 3rd level character, who also happens to be say a Minotaur or Centaur (just guessing around 4HD/4LA, could be off) isn't really that unbalanced or broken.
Not sure if it's that strong or not.
My upcoming game (well, starting in two sessions), is relatively powerful.
We're going to be 'Gestalt'.
A monstrous progression race is a valid choice.
But the balance to that, is that it occupies both sides of the build, until the racial progression is played out.
Once that's done, the character can take classes on each side of their build.
So far, no one is interested in a monstrous ('Savage Species' style) progression, starting at level one.
We're using a progression built by a guy on the Paizo boards, where each race doesn't have LA, each class/racial level has a HD at every level.
I'm pretty sure, once someone dies and is irrecoverable, or just doesn't want to continue their previous character... they'll look at a monstrous progression, which is similar to the idea of Level Adjustments.
Once we're higher level, the extra statistics in particular, can be an attractive option.
The last 'higher powered' game, had monstrous races occupying only one side of the build.
From experience, that's kind of overpowering in relation to non-monstrous progressions.
If you're only interested in one aspect of the character... say Rogue... full BAB and lots of STR/DEX from a racial progression is an option.
With say Quickling on one side... that's a lot of DEX and a lot of Movement...
But occupying both sides of the build... so far, no one thinks that's a good option; occupying only one side of the build, everyone thought it was the best option.
We'll see how it goes.
