Hi Dreamer, it's a little tough to be specific on style and sound comparison to the Pa2X since I have had a Tyros 4 for 2 years, but I am loving the Pa900. The styles are very natural and well balanced, and I have been able to find sounds very quickly that sound good to my ear.

Obvious differences like the significantly lower weight is a great plus for me, even though I miss the 76 keys, but then I've coped just fine with the Tyros, arranged some pieces in different keys to accommodate.

I personally have been struggling with the keybed feel, because it is so different from the Yamaha. It reminded me of the feel of the Pa2X in that, as I mentioned above, you have to use quite a lot of pressure if you play the key at the inside. The Pa2X had a longer key movement, closer to a piano. With large hands it's easy to get to the inside, especially on the black notes, if you are playing a fuller right hand part. I have changed the sensitivity to soft, and am confident that I'll get used to it. Btw, I seem to be alone in this, others like the fact that you need to exert more pressure.

There is a hard disk installed, I believe the SD card is an option, and have not looked at that. I use a USB stick to update the OS and to backup what's on my hard drive.

Boot-up time is slow compared to the Tyros, frankly it does not seem much quicker than the Pa2X, but that's really not a problem as long as the keyboard is reliable once powered up! I'm praying that will be the case.