Doug was right about 1 thing-it is a marketing ploy. Smaller keys means less material less material means lower costs. Since the 2100 is coming in at the same pricepoint as the 2000 Yamaha can have a bigger margin on each piece sold. Remember 2 things: the only way to increase your margin per piece is to increase the selling price, or decrease the costs. Yamaha chose to decrease the costs, and cut corners when, and wherever possible. Also, no manufacturer will ever produce the perfect product that lasts forever-in time it would put themselves out of business. I get Consumer Reports mag, and every month there is a story about shrinking consumer good products, or packaging. It is not very noticable on the product unless your read the fine print, or in your case get out a ruler and measure. But business is just that-they aren't going to loose money. If you want bigger keys, and Yamaha incorporates them into their next product release they will be probably more fragile and break easier, or maybe a more important feature will be left off. No manufacturer will ever eat production costs. They will either pass them on to customers via price increases, or cut corners somewhere else on the product.