Bigger pieces might give longer burn if your stove is leaky. If the stove is tight size should not matter. In fact you can put more pounds of wood in the stove with smaller wood.(Smaller wood drys better) Less open space. Think or the sand and stone demo. The smaller wood will burn more completely giving more BTUs per pound of wood. If your stove will not hold over night on small stuff check for leaks. Check that door gasket with a dollar bill. If its a cast unit check all joint fro the clean wash marks where the air is coming in. good gasket sealed joints will let you get the most out of your stove.
Larger splits give less air space between the splits than a load of smaller splits will do. There are many enough on here that know and use this practice as tried and true. Has nothing to do with air leaks, and everything to do with air space between the splits. The only way your going to get the same burn with a load of smaller splits as you will with a bunch of smaller ones, is if the smaller splits fit damn near perfectly tight together which ain't never gonna happen with split cord wood.
"Bigger pieces might give longer burn if your stove is leaky." ... This statement alone says all that need be said. If smalls burned the same way, then what difference would an air leak mean on big splits Vs. small ones?
Again more air channels and air air to wood surface with smalls Vs. large splits.
Burning the same stove with a load of large splits Vs. small splits will yield shorter burn times with the small splits with or without an air leak.
It is all in the air space between the splits. Typically more air space = hotter burning, and shorter lasting burn.
I also know that a load of too many large splits are loaded, the wood will actually burn poorly due to lack of air to wood surface & flow of the air.
"With the air control on todays stoves you can hold fire well with smaller pieces. Smaller pieces mean more surface area burning"
Again, you are contradicting yourself. You said yourself smaller pcs mean more surface area burning. Which also equates to faster consumption.
The one thing small loads will do is burn hotter, and faster.
And 6 months split and stacked wood is no where near enough time in PA for wood to burn. I don't care where you got the info, they are misinformed.
Try and burn some oak, hickory etc after only six months split( unless maybe if you splits 1" x 1" splits). I guarantee you will not be happy with the burn, and be one of those on here complaining the stove will not get a high enough temp, blaming the stove for crappy performance, and have a ton of creo at sweep time. Throw a full load of those size splits in your firebox and let us know how long that burn time is, and how hot that temp skyrocketed to.
I would not even burn pipe only after 6 months, nor poplar.