Very good comparison Robotech. The only thing I didn't see mentioned is stability control. All RLs have it, but most (or maybe all) 2.4s do not.
The RL does have a somewhat stiffer suspension. In some cases this is better, but in others it is worse. On anything but glass-smooth pavement I think that the 2.4 is easier to control, although a better driver is probably going to disagree.
Either model could have been abused, just as either could have been lovingly cared for, so it is important to do a careful inspection. I would consider performance modifications more of a danger sign for potential abuse.
I have one of each, and regularly drive both of them. Except for the power difference the cars might as well be the same, as every other difference is cosmetic and parts can be interchanged to make them look identical.
Sky NA 2007 Midnight Blue
Sky RL 2008 Carbon Flash - Naked