If you are wearing Freedom armor (magic item compendium), do you ignore the maximum dexterity bonus that normally applies to armor?
Ask your DM
The spell certainly could be read as allowing you to ignore them. I’ve never played with anyone who did read it that way, but I can definitely see it.
Ultimately, freedom of movement’s claim that it frees you from all hindrances and allows you to always move freely no matter what, just cannot be literally true. That leads to you being completely incorporeal, which is generally a very high-level effect, not a 4th-level one. So there have to be limits on freedom of movement despite its basic claim that seems rather unlimited.
Where to draw the line? No one can answer that authoritatively; everybody has their own opinions, and it’s impossible, under the rules, to truly justify any given interpretation as superior to another.
Note that continual freedom of movement is really good no matter what you do. It’s pretty high on the list of must-have item effects.
But a +6-equivalent armor (including the mandatory base +1 bonus) costs 36,000 gp and change, while a ring of freedom of movement is 40,000 gp. I think the ring is a better choice here, because the options for armor/shield slots are better than those for rings. Between the ring of freedom of movement, and putting, say, heavy fortification on your armor and soulfire on your shield, you become immune to a lot of things. Since soulfire and heavy fortification don’t have ring options, I like the ring of freedom of movement more than than the freedom armor.
As for increasing maximum Dexterity, making an armor from mithral and applying the nimbleness property (a relatively-cheap +1-equivalent) increases an armor’s maximum Dexterity limit by 3, which is quite sizable.
If you have really high Dexterity, Races of Stone has an armor called “gnomish twist cloth” which has a +1 armor bonus to AC, no maximum Dexterity at all, and, if you take Exotic Armor Proficiency in it, you also get to apply its armor bonus to AC to touch attacks. The last is only a +2 bonus most of the time (native +1 bonus, then the +1 enhancement bonus), which is not worth a feat, but still kind of nifty. Various other very-high-maximum-Dexterity light armors exist, like nightscale’s +6 and spidersilk’s +8.
The freedom armor description says "as if affected by the freedom of movement spell"
A freedom of movement spell has three effects:
- You can move and attack normally even under the influence of magic that usually impedes movement (this does not include instantaneous magic due to how instantaneous works)
- You automaticaly succed on any grapple check to avoid grappling, as well as any grapple or Escape Artist checks to escape a grapple or pin
- You can move and attack (provided that the weapon is wielded in the hand rather than hurled) normaly underwater (but not breathe)
Ignoring the maximum dexterity bonus of armor is not any of these things