One of the issues that has plagued the Palladium system has been balance between the races. Well, balance in general, but we're taking baby steps here.
For the most part, races seem to be either overwhelming or underwhelming compared to humans, with very few of them hitting that sweet spot of simply being whelming. Overwhelming is practically a Rifts trademark. Underwhelming is generally the province of Palladium Fantasy, but it does have some exceptions.
As I'm designing BTR, the question comes up: How do I balance races against each other?
Balance everything against humans: Since most of our real life experience has to do with humans, this is the "default" race in most games. So fantasy and alien races are often compared against that standard. Under this scheme, most of the races will only have an advantage over humans if they have some balancing detriment.
Balance humans against everything else: This is the route that most modern versions of D&D use. Every race gets something cool, even humans. The downside is that this requires that humans get something. But while the bonuses that elves get are intended to make them feel more "elvish", it's damned difficult to come up with bonuses to make humans cool. Because there's that need to treat them as "generic" so whatever they get has to be completely flavorless.
Give the races a cost: Many point-based systems do this. Being human costs 0 points, while other races must pay for their abilities. So non-humans will have abilities or bonuses specific to their kinds, humans have the advantage of spending all of their points on personal abilities.
Palladium has currently given little thought to balancing humans against other races. It's not as bad in Palladium Fantasy, where the bonuses that the other races get are not so overwhelming, but it can still be an issue. In old school D&D, humans could take any class and ascend to the maximum level within that class, while non-humans were limited in classes and levels. When Palladium Fantasy did away with these restrictions (which many people considered an improvement), they failed to offer another way to make humans a compelling choice for PCs, leaving them somewhat behind the curve.
Rifts does try to make humans a compelling choice, but does so in a rather ham-handed way. The Coalition's paranoia regarding non-humans and supernatural powers means that anytime your party has to do business with the Coalition, they have to send in the human. So in order to make humans a compelling choice for players throughout Rifts Earth, the Coalition has to be everywhere. (It also makes sure that your money is good wherever you go) Which is one of the most unrealistic elements of the setting: The idea that this upstart government in this post-apocalyptic world has such a vast influence.
My current plan is actually "A little from Column A and a little from Column B". Each race will have a modest set of bonuses at character creation, and will also have advancement options to give more flavor to their race. Race specific milestones, spell lists, and such.