Yamaha is certainly a reputable brand. I still have my digital piano (a Clavinova). It's still in near mint condition after 10 years. I can't say much for the keyboard itself, but I know I'd recommend Yamaha any day.
Two years is nothing for a keyboard. Pianos seem to have more of an investment feel - something that you purchase because you can see yourself playing it 10 years from now - than guitars do in my opinion.
To quote a great man, "If it sounds good, it is good."