Get an S4 or wait for the A7???
In the meantime, you can get a model that has been out for 1 year and, depending on your penchant for upgrades, some are available (exhaust, etc).
The uncertainty of engines available for the A7 dissuades me for the moment. 3.0 is likely to make it but I would sure like to see a diesel here.
For technology, I am guessing the A7 benefits from A8 current equipment more so than the S4.
I am facing a similar dilemma but am on opposite end of spectrums - go for S4 now or hold a couple months as an S8 is coming off lease from a family member. This family member, ironically, is interested in the A7 as well. I am more inclined to go for S8 due to rarity and knowing the history of the car.
My concern is just the fact the A7 is a first year model.





