None. Auto brakes are the same. Options on the 170 and standard on the 190 but if installed they are identical. Unlike the CRJ200 v 700 which has different systems (fuel,elec, etc) not to mention the leading edges, there is no difference between the 170 and 190. There are a few additions such as tail strike protection using the RA and rate limiter, and the over wing exits and a few others but I don't consider them nearly as different as the CRJ differences.