The PX-150 is the lowest on the totem pole of all their new digital pianos that came out last fall. It only has 18 voices. It comes with cheap speakers. There's no LCD screen. No line outs, just two 1/4" TRS headphone jacks. All the bells and whistles are absent. It is MIDI compliant.

However, the PX-150 has the same key bed as their most expensive digital pianos and the same sound engine for the 18 voices it does have.

This is what I think is cool about Casio digital pianos:

1. The keys have a subtle texture so they feel like real wood, and your fingers don't slide off the black keys as easily.
2. The lower keys are progressively heavier and slower like a real grand piano.
3. The keyboard has Sustain Resonance. When you press on the damper pedal, you hear the soft sound you hear on a real grand. If you play a note with the damper pressed, you hear the sound of all the other strings vibrating.
4. The keys transmit high resolution MIDI. Instead of 127 different velocity values there are 16,256.
5. The new keyboards have 3 times as much memory as the older models and use loss-less compression. When you let a low note ring out, it rings out for a long time, and you don't hear looping.
6. The grand pianos and the electric pianos sound fantastic through headphones. I haven't hooked it up to speakers yet. The onboard speakers sound tinny and lackluster, however.

If I want to press buttons and get a dazzling array of sounds and rhythms, I have my PSR-S950, but if I just want a great grand piano, I have my under $500 Casio.

It feels much better than p105 or 35 and none of them has midi ( usb only).

I just hooked up my PX-150 to my Logitech Z-2300 speakers. It really sounds exquisite. The bass notes vibrate through the floor and through my body, and the keyboard sounds balanced from bottom to top.

I can't believe that for just over $700 (keyboard + wooden stand + three pedal footboard + Logitech speakers) I can have something so close to an expensive grand piano.