If the two choices were the same price (Preferred Value vs Standard Moderate), I'd defintiely go with the Moderate.
A Preferred Value room just upgrades the room's location. A Moderate room (even the Standard) is larger than a Value room, and the resorts have nicer, more "grown-up" theming (not that there's anything wrong with the Value theming...) and more amenities.
But I guess it's up to you what "similar in price" means, and when you're going... Looking at the prices for Jan 1-15, for example, a Preferred Value is $97, where a Standard Moderate is $149. I'm not sure a $50/night difference would be considered "similar prices".
-Rob