Due to the high number of requests for Martinique and Trinidad North, they both are now considered Preferred buildings, and have a higher cost than the other "islands". The pricing is the same as a water/pool view, however, if you want the Preferred location you lose the choice of view as you are paying for the guaranteed building location.
They do run an internal bus - and after you check in they will use a van to take you to your room with your luggage, if you have it with you.
Don't forget the bridge in the center that connects Aruba/Jamaica with Old Port Royale.
Personally, I would avoid Trinidad South at all costs, unless you like seclusion.
Here is what I posted in an other thread.
I have stayed at CBR Sept. 28 to Oct.2 2007.
The rooms are slightly larger than other Moderate resorts.
Has fridge in the room but think all Moderates have them. Ceiling fan in room
Each Island or "Village" area has its own
1. Quiet pool
2. White sand Beach
3. Hammocks on the Beach and
4. Bus stop. (Covered)
Just refurbished the feature pool and it is very nice
Stayed in Aruba section and was near the footbridge to Food court and feature pool which was a short peaceful walk each day. The island you cross over using the footbridge had more hammocks, picnic tables and nice lush landscaping and local birds around sometimes. (Might have been a small covered sitting area there also but memory is fading.)
The food court was nice and the gift shop area was also this is were the concierge area is.
BUS System.
I DID NOT have any problems with the bus system. There is a dedicated internal bus system with covered waiting areas for each village.
So if you don't want to walk just sit and relax in the covered area till bus comes and get off at the stop you want.
Yes, the bus stops at each village but did not have a problem with it. Aruba was early in schedule during day so got on and just short waits and to the parks you go.
At night it was I think next to last. If you do not want to wait then you can get off at Old Port Royale and walk over to Aruba using footbridge which I did a few times and was not bad at all. Has a full service sit down restaurant which I didn't get to try.
To answer 1 of your questions, yes the main check-in building is separate from the buildings with rooms "villages". But I stayed in Aruba section and it was not that far a walk at least for me. The foot bridge is right there and you cross over it to the main pool and food court and again this was a short pleasant walk for me.(Old Port Royale area)
As stated by DisneyJoe they have an internal bus and I do seem to remember the van also.
Since they have a bus and or van to take you to village then I wouldn't worry. I feel Aruba was a great area.
If you have physical problems that are made worse when walking then go for the preferred locations.
EXTRA: During day bus goes. . Jamaica, Aruba, Barbados, Martinique, Old Port Royale, Trinidad North and then Trinidad South
At night. . Martinique, Old Port Royale, Trinidad North, Trinidad South, Jamaica, Aruba and then Barbados.
Hope this helps you.