For quality of after sales service, and build quality, it's the Yamaha over the Casio.
We see too many posts re problems with Casio actions: sticking or wobbling keys. That does not mean that all Casios have these problems, it does mean that it would be a good idea to know the store's return policy.
FWIW, I actually see cautionary posts like this at a rate of 20x any actual posts of owner complaints. It's like a broken record.
As for the comment about after sales service, I'm just curious about KurtZ's experience. I've found both to be good, and both to be occasionally bureaucratic (not unexpected as these are multi-billion dollar companies).
It's funny but on this forum, most recommendations for Casio are given begrudgingly, and yet the products from the Casio's Privia line are winning critical acclaim from industry staples like Keyboard Magazine here
and MMR + others like the NY Times
. These models all share the same action & feel. Casio is definitely winning the real world battle for customers in their target price range.
As for the touch, both are entry level DPs ... they are remarkable for the price*. You have to include "for the price" and essentially the difference between the two essentially amounts to preference, not a measurable better or worse in regards to accuracy. Touch on acoustic pianos varies tremendously even among comparable, expensive brands.
Whichever you decide, the questions you need to ask are simple: will the DP do what I ask? is this the price I'm willing to pay? do I like it?
I have significantly more experience with Yamaha acoustic pianos, but I see a tendency there that parallels in the digital world. Yamaha makes different levels of products, and often their hard earned professional accolades for their top products are then passed by association to their entry-level products. Is this necessarily fair? In the Acoustic piano world, Yamaha faces an onslaught of high value competitors, especially for their lower line models.
Casio doesn't yet make any $3000 DPs, but their cheap DPs are good and I think they put a lot of pressure on Yamaha.
Both are good, but don't let anyone scare you from a Privia.