So in the Sprinter example the difference is only 3lbs? Hardly anything to worry about (er slide vs no slide weght that is--as far as the ccc yeah it needs to go on a diet).
Ah but the Sunseeker 2400B & 2400Q: They both have slides, just one is bigger than the other:
2400B:
2400Q:
So they both have the mechanism.
Oh and one has the kitchen on one side vs the other which has the kitchen on the other side. Make it even more interesting that they are only 3lbs different.
Also note that the 2400W has a very similar floorplan (looks like it is now discontinued, however).