So what about powered Speakers?

In 1975-6 I had a pair of Braun LV1020s which were internally tri-amplified with relatively wimpy and noisy cap coupled amps with 60/30/15W per speaker, and all analog filter networks, but which were glorious.  I moved on, but today, those wonderful drivers and cabinets could be outfitted with Class D modules and DSP crossovers, for dead quiet distortion free amplification with PEQ tweaking via smartphone. They would cost $25K at least, too. 

Were in forced into a position to only have a self-powered option, I would heartily recommend these:

Transparent One Encore Plus - Vanatoo

I heard these a couple of years ago at PAF and was really impressed with them. Then when the owner of the company added in a subwoofer, I was blown away at how well it all sounded. Note: This was in a hotel room but I think in a not too much larger space they would do quite well. I almost bought a set for my desktop system.

Happy listening.

Active speakers ("powered" can mean they're still passively configured, just with built-in amps) span quite the varieties, both in size, price and quality. If you're more of an entrepreneur and don't mind diving into the rabbit hole of doing filter settings by yourself, you go outboard active and get to choose the components just as you see fit - same as you would passively. No excuses here; get familiar with what active can do with separates by your own hands and abilities, and without the bloody power and quality draining complex, passive filters in between. 

Going by the OP's subject however, i.e.: bundled active speakers, imagine finding the "balls to the wall" active filter-amp-speaker (and possibly DAC in addition) system that suits your ears and dreams and that has the benefit of providing for a much improved amp-to-driver interface, and then forget about it and start concentrating on improving everything around it from the basis of a much more resolving and transparent (active) speaker system with a major bottleneck less to deal with.

Sometimes you get the feeling that the conservative, passively configured speakers only folks believe active speakers don't give you the opportunity to tweak the system in which they're implemented - that is, as if it's a negative - but it's actually more about the blessing of not having to deal with tweaking in the primary area of amp-to-driver interfacing (something that, conversely, would be necessitated from a passive context, though to a much lesser outcome), and instead being able to focus on fine tuning from said better, active outset. For those who don't believe an active speaker context can be true high-end and everything you want it to be, dig a little deeper.  

Ad nauseam diatribe on this site.  More respected opinions would come from those who have lived for some years with active speakers.  I own ATC 19A, 40A and 50A floor standers.  The 19s and 40s for over 15 years.  No failures.  I'm sure they could fail.  But then near anything can.

If one does not like actives for whatever reasons previously listed, then by all means do not purchase them.  They are not for you.  But the arguments against, oft  by non-owners, rings a bit hollow.  I don't do missionary work and couldn't care less about what occupies others homes.  Love them or stay away.  That's the beauty.  We all get to choose which sandbox we want to play in.

@zlone 

I doubt it can get to the level of a truly great system.

If you did get to the true high end and commensurate cost

It's subjective because you know you're hearing what the designers intended with the active amps. Obviously, most here don't like class D and want some artificial tricks from an amp. But I think KEF is class A + D.