Yes, one difference would be water requirements.
Also, diet could play HUGE factor(especially when dealing with Malawi cichlids)
Below I have listed all of the cichlid groups:
Rift Lake Cichlids:
Which are from:
Lake Malawi, Lake Tanganyika, Lake Victoria
This is where you will find alot of hard water loving cichlids.
Some of the more popular ones would be: Haps, Peacocks, Mbunas, Shelldwellers, Frontosas, etc, etc
West African (Riverine) Cichlids:
Though they are african, in these parts the water is soft to neutral. So the fish that come from here usually have opposite water preferences than their rift lake counterparts.
The cichlids that come from here are cichlids like: Jewel cichlids and Kribs
South American (Amazon) Cichlids:
The water in the amazon is usually very soft, but some parts are fairy hard and are actually as high as a ph of 7.6!!
The cichlids that come from here would be cichlids like: Discus, Angels, Apistos, Rams, Keyholes, Severums, Festivums, Blue Acaras, Green Terrors, Oscars(which are now also found in other places of the world).
Central American Cichlids:
The waters here are usually hard.
These cichlids can even be found in North American places like Mexico and even Florida!(i won't get into that)
ALOT of the cichlids that come from here are your "heavy hitters" like: Jack Dempseys, Jags, Doviis, Red Devils, Trimacs, Midas cichlids, Salvinis, Convicts, Umbees, Texas Cichlids, etc, etc
But you'll be glad to know that NOT ALL Central Americans are overley agressive
So basically to sum all of this up........
When it comes to cichlids it's a matter of personal preference, routine maintence, tank space, compatability and some trial and error IMHO
Disclaimer: Yes, I wrote all of the above myself!!