I would say that a pro of Genesis is it's easy adaptability... You can make a huge variety of creatures/characters without having to clutter up your runtimes with a multitude of standalone figures and morphs packs...

The downside is poly-count... much like the Gen 4 Figures, Genesis is higher poly meaning you can't use as many in a scene as you could with older figures, so it really depends on what you intend to use it for... for one or two people in a scene I'd say Genesis and the older Gen 4 figures work well... but if you want that crowd scene you'll probably still want to use the older figures as they aren't quite as resource intensive comparatively...

From my point of view Genesis is better for somethings and not for others.... but that's just my opinion... take it for what you will... :)