These sound quite good!
As do some piano and strings demos.
Comparing it with a Casio is an insult. I think Roland put in very mixed quality here, and as they squeezed in such a vast number of sounds, they obviously chose to compress some of them like brass, but not all.
I guess all in all it is better and more versatile than the BK-5 (and it costs much more than the BK-5), but as I said you can't compare it with the BK-9.
Casio has come a long way, mostly where piano sounds and synth sounds are concerned.
Maybe teh MZ-X which is in the same price range as the E-A7 but blows it away when it comes to functionallity will comvince soundwise. we have to hear them next to eachother to hear the difference..
I dont see hte E-A7 as a step up from the BK series, merely a replacement build in Japan instead of in Italy..
Offcourse it sounds okay, its a Roland afterall, and if you allways liked the Roland sound, there is no reason not to like the E-A7's sound