40k 6th edition (AKA "Flying Transports: Hurray for Flying Transports!")
I've crunched the numbers, read a lot of threads, and have come to the painful realization that until a major errata is made to 6th edition regarding flyers, there are only six competitive army 'types' in tournaments:
1. Imperial Guard
3. Armies that ally with Imperial Guard
4. Armies that ally with Necron
5. (To a lesser extent) Blood Angels/Grey Knights
6. (To a lesser extent) Armies that ally with Blood Angels/Grey Knights
I guess you could say that there's only one type of competitive army right now: those that have access to inexpensive flying transports.
Yes, Blood Angels/Grey Knights Stormravens also have flying transports, but they're generally too expensive to be used in the 'game breaking' way that Night Scythes and Valkyries/Vendettas are used now, except perhaps at the highest point levels, so they're less competitive than the others.
Most armies have some sort of flying unit, but since flying vehicles and flying monstrous creatures can't claim objectives (and as far as I know, only the monstrous creatures can even contest them), it's the transports that can carry troops to claim objectives that cause the trouble.
Here's the problem: after arriving from reserve, flyers can immediately re-enter reserve. You just have them fly in near a table corner, leaving the one table edge and re-entering the other. Why is this broken? Because it enables you to have them all arrive on turn 5. With their speed, they can easily move to any unattended or weakly defended objectives, and drop your troops off on them.
In order to compete, an army without flying transports will have to simultaneously claim/contest the majority of the objectives on the board with units capable of defeating an Imperial Guard unit loaded with special guns (flamers/plasmas/meltas/demo charges), and/or 10 Immortals with a Necron Lord attached.
This changes a game that used to be 5-7 turns of struggle into a 1-3 turn endgame spree, with just about everything being decided by late arriving troops in 5 out of the 6 missions.
So who are the big losers? The only two armies who cannot get access to a flying transport one way or another: Dark Eldar and Tyranids.
How can this be fixed? As I see it, one of two ways: FAQ/Erratas need to either forbid flyers to fly back into reserve the turn they arrive, or allow all reserve/deep striking units to choose whether or not they enter the field or go back into reserve (won't solve the endgame problem, but at least it'll level the playing field).
In short, flying transports have f*cked the game balance in 40k 6th edition the same way magic f*cked it in Warhammer Fantasy 8th edition.
In other words: now's a good time to start playing Necromunda instead.