It's likely that the keyboard is priced so reasonably because of the Casio brand. If the name said Korg or Roland,the tag would probably read $1000.00, or more...
Yep...Casio is a monster company,that has their hands in everything from calculators,to computers,watches...you name it,& have been around since 1957.
Of course though,they've only entered the musical instrument arena since 1980,but they were surprisingly competitive and even more innovative,by not only providing reasonably priced keyboards...but ones such as a synthesizer that had a dual cassette deck & a radio built in....that was a fun keyboard!
It seems to me that the reason that Casio backed off from making pro grade synthesizers for the last 20 years,was probably due to the growing number of competitors & the directions they were going in in the early 90's,perhaps.
That being said,I think that Casio seized the perfect time,whereby the current technology has advanced to a point where they're able to not only compete with other hardware synths by offering more within their production costs,but also to generate an incentive for folks who primarily use software,to reconsider using hardware more(Casio's strategy worked on me)!
Casio's strongest concept & consequent advantage,is innovation, & I think the XW-P1 is a testament to that,as Casio managed to come up with a synth that offers the most fluid & versatile real time control...that includes more physical controls,editing,layering & polyphony over any synth in or near it's price range.
Though Casio has made a notable improvement with it's drawbar organ & the fact that they have triple strike pianos,I don't have any high expectations of their other bread & butter sounds,but from what I've heard thus far,I am impressed overall,at the attention to quality,for the coin.
As for Korg..well..I think they provide a very good bang for the buck in the $1,000 & up range,but anything they've produced for under a grand,has been very disappointing & unusable,in my opinion.
Roland in my honest opinion,has been fleecing the planet with workstation synths & even some of their stand-alone synths for the last 15 years, with truly disappointing factory sounds,while creating sound card libraries with quality sounds at a substantial cost,as a means of extorting the Roland user.
To make matters worse,when Roland does create a synth that is truly inspiring,they focus only on making quality sounds and then eliminate most-if not all,on-board recording options(despite the fact that their synths cost just as much-if not more,than their competitor's workstations).
For some reason,Roland still has a small but loyal cult following...but I don't think that will be enough to sustain Roland for too much longer & they'll be in serious trouble,once Casio begins to gain momentum in the pro market(unless of course,Roland diverges into a radical new direction).
I would really like to see Roland reemerge with synths like the old Super JX-10...but I don't hold any hope of that every happening.
-Thom