Feature:
There weren't any features that I really needed that didn't come with this keyboard, except for a power adapter. I like the Casio-chord feature a lot. It's a good way to mess around with chord progressions if you're not quite sure where to go with a song.

Quality:
Much better than I expected. I wanted a low-cost keyboard to write music with. Now I record music with it, and it gives me the lo-fi sound I crave.

Value:
Out of every musical instrument I've ever purchased, this one has been the best value. I play it every day, and, unlike my guitar, there's no sort of upkeep necessary. Just plug and play, my friends.

Desirability:
I mean, it's a Casio. That's kind of retro-chic, right? Ok, it's plastic and gray. What do you expect?

Sound:
I use this keyboard for home recording purposes. I find that most of the tones sound pretty good with a little reverb added, but some of the higher pitches "buzz" a little too much, so I have to apply filters or use other techniques to make it sound a little less "plastic." Otherwise, I'm mostly content with the tones provided, especially Jazz Guitar and Wood Bass. When mixed just right, these tones can sound very organic.

Overall:
It's been two years now. I'm not ready to upgrade any time soon. Between this keyboard and my editing software, I'm good to go.