At CBR there are two 'extra's you can pay for. You can pay for close to the main building - at this resort, this is a pretty big deal, as it is VERY spread out. You can also pay to stay in the Pirate Themed room. The pirate rooms are as far from the main building as you can get - but having seen some pictures, if that appeals to any of your younger traveling companions, I think the distance could be dealt with.
So if the Pirate room appeals, and you can get the discount on them (though they will be more than 'standard'), I think that would sway me.
The spread-out level of CBR is pretty negative to some people, and POR is not the most compact, but it is more compact. There is an internal bus loop at CBR, though, that will take you to the main building if you don't want to walk it. At POR, you basically have to walk it. But at both resorts, you can catch a bus to each park nearer your room without having to go to the main bus stop.
If you have young travelers that would really really like the Pirate room, then I'd do CBR (and the cost difference isn't going to break the bank), otherwise I'd do POR for your first moderate - because it's not the most compact nor is the most spread out. This is only if the theme appeal isn't substantially different between the two - if one sounds LOTS more fun than the other, then I'd do that one first. That is TOTALLY a personal preference.