I am a rookie & wanted to learn to play keyboard. I researched a lot before buying this one so...
Casio Vs Yamaha If you are a beginner & care more about functions than sound quality , go with Casio. If you want a keyboard with louder & good quality speakers for performance , go with Yamaha.
Note : Please don't buy Yamaha keyboards from on-line retailers as there is some sort of warranty issue. In case of Casio , you can buy online but there is an issue of not receiving adapters for many customers so choose your seller carefully. I would recommend Crystalarc Lifestyle as they are authorized Casio sellers & I received an official Casio adapter with my keyboard.
Buy CTK 3500 if 1. You want touch response 2. You want USB-B port to connect your pc 3. You want Chordana Play connectivity 4. You want a pitch control wheel
Now about the keyboard Speakers : I found them really nice & loud enough for personal use.. not much for performance though Keys : Really soft & nice to feel Functions : There are a lot of functions & once you read the manual , it is becomes easy to use There is an inbuilt step lesson teaching function which is similar to Chordana but way more awesome
About Chordana App : To be frank I have used the app & I didn't find it much helpful. Even after connecting the app didn't recognize my keyboard keys in the step lesson mode.. anyway still you can use the app to transfer songs to the keyboard itself which is way more useful.
Must buy accessories for beginners : 1. Dust Cover 2. Travel Cover 3. Usb A-B cable 4. Note Stickers
If you interested in buying Casio keyboards & don't mind paying online then I would suggest you to buy from casioshopindia.in