Variant's page

So given this snippet from the Summoner Eidolon page:

Size: When summoned, an avian eidolon is Small unless it spends 2 points from its evolution pool. At 5th level, a Medium or larger avian eidolon's flight speed increases by 40 feet, as if it had 2 more points in the flight evolution; Speed 30 ft., fly 30 ft. (good); AC +2 natural armor; Saves Fort (bad), Ref (good), Will (good); Attacks 2 claws (1d3); Ability Scores Str 12, Dex 16, Con 13, Int 7, Wis 10, Cha 11.

And this:

These base forms also note any free evolutions that base form possesses. The bonuses from these free evolutions are already factored into the starting statistics. Alternatively, any one of these base forms can be used to make a Small eidolon. If the eidolon is Small, it gains a +2 bonus to its Dexterity score. It also takes a –4 penalty to its Strength and a –2 penalty to its Constitution. It also gains a +1 size bonus to its AC and attack rolls, a –1 penalty to its CMB and CMD scores, a +2 bonus on its Fly skill checks, and a +4 bonus on its Stealth skill checks. Reduce the damage of all of its attacks by one step (1d6 becomes 1d4, 1d4 becomes 1d3). If this choice is made, the eidolon can be made Medium whenever the summoner can change the eidolon’s evolution pool (which causes it to lose these modifiers for being Small).

Does making it medium mean that the avian eidolon's physical stats become:

Or do they stay the same for both medium and small?

Thanks for the info, that definitely makes sense.

Got a question about the result of having these two abilities:

The Duergar Racial Trait 'Slow and Steady':

Slow and Steady- Duergar have a base speed of 20 feet, but their speed is never modified by armor or encumbrance.

And the Monk special ability 'Fast Movement':

At 3rd level, a monk gains an enhancement bonus to his land speed, as shown on [Table]. A monk in armor or carrying a medium or heavy load loses this extra speed.

So if I'm a level 3 monk (20 + 10 ft without armor), what happens to my speed with armor on? Is it 20 ft, or is it 30 ft?

My assumption is 20 ft, but it doesn't say 'base speed is never modified', so I was hoping there may be a cool interaction here.