Aerial 9 vs Dynaudio Contour S 5.4

Depends on the size of your room. The Aerials are awesome as long as your room is at least 14x20 ft. I don't have any experience with the contours.

Both great speakers and I have experience with both. I prefer the Dynaudios, but as a dealer some bias creeps in.

Both will require a large amount of current to get the most out of them. The Theta is a decent amp and will work just fine, though.

I prefer the top of the Dynaudio's. Bass is pretty much a wash imho, both excel in the lower frequency range. I could live with either for life, but if I had to make a decision, I would choose Dynaudio.

I've owned both. Very different speakers. The Aerials are gutsy and thick sounding but unless you have a large room the bass will be muddy. The Dynaudios are much more detailed & airy, but leaner in the midbass.

I agree - different speakers. I prefer the Aerials though the Dynaudios are right up there. The Aerials are more articulate with tigher bass. "Tuneful" bass as a friend says. The Dynaudios are warmer with more bass punch. IMO, the Aerials are more solid and better built but the Dynaudios again aren't far behind. If you were going to get the 9s, why not move on up to a pair of 20Ts vers 1. I've seen them used for $10k once or twice.