I can't find much solid information about this so was wondering if someone could please help out. I'm currently testing several perks to see which ones are actually worth investing in.

Basically I am wondering - do the Unhindered and Conditioning perks affect movement speed at all or do they just affect the rate of stamina that gets drained when sprinting and carry weight?

I ask because I have a character that wears a mix of heavy and light armor and have saved my game before and after getting the perks and can see NO difference at all in his movement speed either way. I know Bethesda did an awful job describing the perks in a lot of cases, is this another one of those cases i.e. "...and doesn't slow you down when worn" or am I just not seeing the movement speed effect?

It does improve movement speed, by nixing the penalty worn armor has. It should be noticeable with Heavy Armor, unless you were rocking the Steed Stone (which does the exact same thing). Not to mention worn armor won't count against your carry weight.

Are you sure on this though? I have done several tests running from a to b today in full ebony armor and based on my stopwatch the time it takes with and without the perks seems the same. I don't have the steed stone by the way.

The perk/s DEFINITELY decrease stamina drain when sprinting with heavy/light armor and they DEFINITELY decrease the carry weight of heavy/light armor. I just can't find any definitive evidence that the perks affect movement speed at all besides the fact that Bethesda mention it in their description of the perk which doesn't count for much really because "...doesn't slow you down when worn" to them may simply be an alternate/incorrect way of saying "...reduces stamina drain when sprinting".

If there is a speed increase it seems to me that it must be absolutely tiny as in 0.1% - 1% maybe.

*cracks open the Editor*

Ok, what the perks do is forces an armor's weight to zero when you wear it. Theoretically, that will do exactly as stated, provided that movement speed is determined by carry weight, and not by the fact you're wearing armor.

Maybe try a timed test with and without armor?

Thanks very much. I never realised that movement speed was actually affected by carry weight in Skyrim and thought it was simply affected by what you are wearing i.e. if you are naked and have heavy armor in your inventory you will move just as fast as if you are naked and are carrying nothing in your inventory.

I have done a test with the armor on and naked and naked seems to be faster but I can't be 100% sure. I'll keep testing.

I know for a fact that armor does indeed slow you down. Just the other day I was hunting down a full set of ancient Nord armor so I decided to play a game of tag with our favorite friendly ghost near some ruins. Problem was, I couldn't catch up to him, so I took off all my armor and BAM, I caught up to him with no problem.
So if the perk does indeed do exactly what it says, then it should definitely make a differene. It might not be very noticeable unless your trying to catch someone/something running away from you.