Vanatoo speakers - should I get them for hifi sound?

Yes.
I have transparent one encores. Heard them and zeros at a high end show. The room was mobbed and everyone impressed. Including me.
Lots of cutting edge technology applied to deliver a most cost effective product.

I also have KEF Ls 50. metas.  The Vanatoos compare favorably for ~ 1/3 the cost and everything you need.  Just provide the source either digital or analog.  Can be Bluetooth and still sound very good. 

I heard them at a show and thought they were really good for the cost. Maybe you should hear them yourself.
Review in NoAudiophile
Review in ZeroFidelity

I have Vanatoo for my computer office.  They are very nice at close range, but will not fill the room with music.  The KEF LSX are superior, but more expensive.  Both need a subwoofer for deep bass.

Chiming in again, besides owning audioengine and vanatoo zeros I also own some KEF LS50Ws. The KEFs are easily the best as they really are a pretty amazing speaker and flexible given these are active with DSP. They are too large for me to put on a desk or office sized room which is where I use my Vanatoos. I love my Vanatoo Zeros for desk and a small room. If I had a regular or smaller sized room I'd probably opt for the new 1s instead of the Zeros. The audioengines are fine but not the same fidelity as the Vanatoos nor as flexible with setup etc. Hope this is informative.