DP for practicing at night: s51, p155, px150, ...others?

Hi guys, I need an advice on choosing a decent DP: I've been reading lots of threads on this topic, but I really couldn't find an answer to my "dilemma"!
I am studying Information Engineering away from home: I am now living in an apartment where I want to practice at night, so I don't care about the quality of speakers (I will mostly use the DP with my sennheiser's hd 580): the only thing that I want is a fairly good keyboard to practice fingering on pieces like Bach fugues, Beethoven sonatas, Chopin etudes etc. (oh, and at least the possibility of connecting 2 pedals: damper and una corda).

I have tried a few pianos in my local store, from the cheap Casio px-150, to the more expensive Clavinovas clp/cvp and hybrid pianos (that are jaw-dropping!).
Unfortunately my budget is not high at all, around 1000€, so I am NOT going to consider any of the high-end clps or kawais (unfortunately, I haven't had the possibility to try any of the latter).

I've heard good things about yamaha's P155 and Casio PX-150 (I've tried both and I like the Yamaha more); but I recently have seen on Yamaha's site this new arius model, the YDP-S51 (that I can't find in any of my local stores), which has, on the paper, the same GH action of the P155, better "tone generating technology" (pure cf vs awm, 4 layers), 3 pedals and costs about 200 euros less than the p155! (How, and why?)

Has anyone tried this new model? How does it compare to the p155 or casio's px150?
I am fully open to your suggestions,
Thanks in advance!

IMO you should look for or wait for the S51. I like the P-155 we have a lot. We both preferred it to the Casio.
Did not know about the S51.
On the other hand, there will always be something better coming.

Thank you for your response.
I agree that the p155 is better than the px150: now I hope to find someone who tried both the p155 and the s51 and will give me a feedback!
(But any other suggestion in the 0-1200€ price range is welcome!)

I'm a bit surprised that there is very little information on the internet (reviews, demonstrations, etc.) about the new S51. How long does it normally take for new models to catch on????? I'd love to try one out for myself. Right now I'm trying to decide between a CP-33 and a P-155. Might delay that decision a bit longer.......

The P155 is very, very often recommended in this forum primarily because in the US it is a super-good buy. Significantly less expensive than its peers. It's generally (or used to be) kind of true that stage-type pianos are cheap in the US while consoles are expensive--perhaps in recognition of the fact that pro musicians are poor and people buying pianos for the living room are less so. In Europe you tend to find the reverse situation, where the retailers want to bleed the pros.

Now, the P155 is not exactly a pro instrument, but the form factor lends itself to gigging and other activities a pro might engage in.

Anyway, at the end of the day, the Arius line is cheaper than the P series in Europe and the reverse is true in the US. So your best bet is to grab an arius unless you need the portability.

I am surprised too for the lack of information relating to the s51!

gvfarns, you're right: here the p155 costs about 1100€, whether the price of a brand new s51 is around 900€, and I truly can't figure out the why of this big difference in their price: the s51 is newer and -at least on the paper- better than the p155. Is it possible that Yamaha makes us pay 200€ more for an older product, only for its form factor (and so its portability)?

I hope that I will be able to try it in a near future, but for now I have to rely on someone who already did!
My questions are: is it a solid instrument? Is the keyboard really the same one of the p155's? How does it sound through its speakers and headphones? Is it comparable to superior models like the clp-430?
Can someone list some pros and cons of this product?

I recently played the s51 at a Yamaha dealer (have yet to see it at the chain stores).
First off, it is more of a console of course than the P155. Second, I found it to have a nice darker general tone compared to the P155.
Even though it uses the same Pure CF sound engine as the P105 I would describe it as sounding more "woody" than the P105 and more pleasant.
I played some of the CLP's such as the 406,408,470; one of the key differences is some of those models offer 4 variations of the grand piano; perhaps 4 speakers with more wattage.'
The arius has the main piano sound, a brighter variation and 2 speakers total; which is not a bad thing- you just get a little more with the CLP.
I assume you are not considering the 105 because of GHS- I know people don't like it here and I can understand,

Now here, the P155 is $1,000 (can get for $850) after coupon but the dealer told me the YDP S51 was either $1800 or $1900- which I think was ticketed high.

I would still though get the S51 though over the 155

Thank you for the useful feedback: I am really leaning towards the s51 right now!
I will probably order it online, even if I have never tried it before.
Other feedbacks would be very very welcome, thank you all for the support!

I wonder if the small framed S51 and similar models proguced by other manufacturers will take off - one would be ideal for my house, and I could gig with it too if necessary.