Hello,
I rarely visit the Yamaha forum, it was a coicident I read your message. I do not know know what Roland you are refering to.
Here is the deal:
Piano sound quality:
Yamaha clavinova beats SK880 big time. It beats every single portable synth,keyboard,workstation on the face of the earth.
Synth features/ Sequencer features:
Yamaha Clavinova was not designed for this. SK880 is known to have the best sequencer that is logical to use and very exensive (requires some time to learn). Also SK880 has an excellent synth.
Weighted Keys:
Clavinova wins
Portability:
Sk880 is portable ofcourse, but note that it is 90 pounds.
Other features:
SK880 wins with programability, auto-accompaniment and price.
do not forget you need to buy external amps for sk880.
As a piano player, the most important thing is the sound of piano. SK880 seems to have all the features you need. However, it lacks a decent piano sound. Although arranger keyboards in general suffer from the same problem, excellent piano sound is a must in my opinion.
Here is what I recommend:
1) play and listen to SK880 for very long time. Make sure you try the Sk880 and not WK8, since you want to try the feel of the 88 keys and sample the quality of the sound at the very high/low octaves.
2) investigate other piano samples that can be loaded to sk880. Investigate piano modules you can connect to the keyboard via midi.
3) If it turns out that sk880 is not good enough, think of buying Yamaha P80 and combine it with wk8 or wk6 or any other arranger keyboard.
If you have other questions, come to GENERAL MUSIC forum and post your questions there.