I just finished looking over this in a bit more detail and... wow... that stuff is hot!
If I understand this correctly, having a masterwork pure mythril tower shield, pure mythril plate mail, and pure mythril weapon would give the following benefits:
Armor/Shieldno max Dex to AC or slow movement for using heavy armor
no attack penalty from tower shield
Freedom of Movement + Haste, 24/7
add half BAB to AC (stacking for armor and shield?)
character gets hardness equal to half armor bonus (stacking for armor and shield?)
half armor bonus (stacking for armor and shield?) added to touch AC
Weapondamage as one size larger
natural 1 isn't an automatic miss
add BAB to damage
And it looks like it would only "cost" 200 gp more per piece, so a total of 600 extra gp. Meaning you could afford this as early as level 3ish. Let's say we slap this on a level 4 crusader or warblade. In total, we'd get:
+10 armor bonus
+6 shield bonus
+8 to touch AC
+4 damage (average, if on a greatsword)
Freedom of Movement
Haste
Hardness 8 (or 5, if they don't stack)
Numbers wise, I think this guy is going to clearly come out ahead of a warblade/crusader 4 who isn't using Pure Crafting items.