Starting in TransportsI believe it is this part that people are finding uncomfortable, and perhaps where we should concentrate the discussion.
I think the Wraithguard example is somewhat of a red herring; the Eldar lists all have Storm Serpents which can be used to deliver the upgraded Guardian formation to the same place; and at full strength as well!
A more reasonable example might be to consider how Orks can abuse the use of the Landa. For example buy a small mob, upgrade with 4x Dreadnoughts and discard the boys to fit inside - a 380 point air assault formation with 2x nobs, 2x grots and 4x dreadnoughts. Alternatively, buy 8x Killa cans for a 400 point air assault formation with 2x nobs, 2x grots and 8x Killa cans.
The issue with the above is that the Ork AV walkers cannot be transported by other means, so are much less likely to be able to get into the same advanced position (the Ork Drop Rock is currently unnofficial, and the Battlecruzer is slow and steady). Obviously the resulting air assault with up to 8x extra MW attacks will be very potent. However, the player has spent ~20% of his 3K total on two formations, and still runs the risk of the Landa being shot down. Also, the opponent knows the air assault is coming and can set up his forces to receive them.
So, are there any other 'abusive' examples in those lists with air-transports, how can they be 'abused' and what are the real concerns on "fairness"
(even though all is 'fair' in Love and war
)