The reason the RAs don't work is because pilots don't follow them. The Russians got it completely wrong. Simple. In my opinion having pilots trying to second-guess or outwit the TCAS by attempting to dodge other aircraft visually should be left to fighter pilots. You have no idea what the other pilot might do during an encounter that will, in all probability, be over in a few seconds. We don't have time to visually assess the appropriateness of a RA and then do it.
Leave it to the TCAS.
As for overshooting the VS during an RA, that's training. In a typical jet at typical speeds and levels, 1° of pitch attitude change will result in a VS change equal to your Mach No x 1000. If you're doing Mach 0.7, 1° will result in about 700fpm VS change. Not very much pitch change is required to comply with a VS RA (and you have 5 secs to achieve it). Practice it in the SIM. Your life may depend on it one day.