Best active speaker

Check out the avi adm9.1s + subwoofer. Remote controlled analog pre, DAC and active speakers all in one cabinet for around $4500 including the subwoofer. What HiFi just reviewed them.

Along with ATC, I would suggest also auditioning the Adam powered speakers. They use a Class D amplifier for the woofer; not sure what the fully powered version uses for the other drivers. I was very impressed with them, particularly due to their ribbon midrange and tweeter drivers, a very open and airy, "fast" sound akin to what you hear in live music.

ATC is the way to go. Sound is better, in my opinion.

Can't go wrong with ATC but you know that.

Consider also Focal Twin 6 - a real bargain in active designs and obviously a step up from the passive electra 1007 (but you lose all that pretty and very expensive cosmetics for better sound and more expensive stuff inside the box).

Large PMC's have clones of ATC's famous mid range (emulation = sincerest form of flattery). So that is another extremely good choice with more bass on PMC's than with ATC. Plus the excellent Volt woofers with external brackets/heat sinks look like something out of a Batman movie - very very cool.

Finally Barefoot MM27 may be worth checking out if you want an extremely small package that will have people picking up their jaws off the floor when you fire them up.

Salagar uses Icepower amps for their active line of speakers.
ATC is very good but I must say very energy wasteful. The heatsinks are hot to touch even when not in use. I read in HDD forum according to AVIhifi founder which is an ex ATC engineer that he finds ATC outdated being that they are spending way too much money on old technology that can't compete with the current ones.
Goldmund has great active speakers as well except they are insanely expensive.
Linn and Naim are great proponents of active loudspeakers.
Dynaudio has some great models as well.
Of course there's B&O that owns the Icepower technology.
If I don't mind the hassle and risk. I will get a deqx crossover with digital outputs connected with Nad M2 pure digital amplifiers with some state of the art loudspeakers.
The so called Class D is going to be outdated soon.