Training speed on it is 98 compared to 320 on the barracks. It has 4 upgrades with that tech, the first of which brings it to 113. If they all do about the same I suspect it would be at 158-160. If the flying academy was fully leveled, 40% would bring it to about 220-225. I know the units from here are great in Chapter 16, but I do not know how good they are in woodelves.
Judging by Karvest's message, I think they aren't that strong yet, so lower production...
Well, of course 3 stars troops are better than 2 stars troops, but I seem to remeber that 2 stars MC troops were not so bad.
Speed depends on building level and level of related AW: if you have lv 30 Needles of course MC speed to be equal needs lv 30 Flying Academy For sure in chapter 15 (end) you need to have fully upgraded MC and Flying Academy: maybe you will need some time to up both ;-)