I've been playing piano my entire life, and I can tell you I've played on a lot of pianos/keyboards! Name the brand, I've played it. One thing I can tell you, is that any digital piano will benefit you far more than a portable keyboard ever will. Keyboards are very cheap, which make them appealing, however for a serious piano player these are just not comparable. If you (or your children) are serious about learning piano, digital pianos are the way to go.
Even though there are tons of digital piano brands out there, there are actually only two brands that meet a professional piano players standards of quality. These brands aren't necessarily the highest price either, because the lower-quality brands like to up their price so you think you are still getting a great piano.
The best digital piano brands are Yamaha and Roland. No professional piano player will argue with you on this one. Yamaha and Roland take out any other brand, no competition. However, deciding which is better of the two can be a controversial subject among pianists.
For me, I love Yamahas and Rolands. I would never ever buy any other brand than one of these two, and you shouldn't either or else you will waste your money. Yamaha and Roland dominate the digital piano market by far, with their impressive and realistic acoustic piano sounds, and the quality of their weighted keys. No other brand can compare.
So what are the major differences between Yamaha and Rolands? Well, there aren't many, really. In my opinion, it is just too hard to decide between Roland and Yamaha. I own a Yamaha (click the link at the bottom of this article for a review of the piano I own) and I love it. Yamaha's are great because they're quality is equal to that of a Roland, but they are almost always lower in price. However, Rolands higher end models offer the best functionality and the most sounds, but this is usually irrelevant for the beginning player.
