They only teach you as a player them and give you double PP (XP) on kills. Being a vegas clone alcohol is everywhere for HP but you get sick after 3, but you can most for a painkiller drink reducing damage by half and healing nicely (and omits the sickness!)
In 2 they have some cheese protection in retaliation moves and I-frames, but also are a bit easier to wing the fights if you didn't expect them.
In 1 psychos could easily combo you to death or destroy you in seconds, but you could also cheese them with some knowledge. Biggest tip is the difficulty balancing is different between the 2.
