Quoting si1foo, reply 21rook needs the speed boost because most people get boots of speed and rook already has a - on the speed soo anklet makes up for it
Rook most definately does not need a speed boost. Even with the anklet, every demigod is still faster than you and they will still catch you. I play rook all the time and hands down the 2 best items are blood of the fallen and the dark crimson vial.
Blood of the Fallen is far superior I agree. It is so amazingly easy for ANY enemy DG to have the speed advantage on you... even the anklet increases you to only 6.21, still slower than beast and erebus. And even one level in maim from regulus drops you down under his speed. Comparing that to an increase of 800 HP and a decent bit of regen... there isn't much comparison.
Don't try to chase people down, it probably isn't going to work anyway.
It is frustrating to die while trying to run away... or at least that is what my opponents tell me.
Don't put yourself in the situation where you have to run.
Edit: Y'know, if you really want +25% speed, save the favor slot for something else, and just get a wand of speed, and learn to activate it with your non mouse hand. There's your speed right there, and you didn't have to use your one favor slot for it.