Should I still braise a roast beforehand if I'm going to cook it in a crock pot?

Braising a roast would give it extra flavor and a nice color before putting it in a crock pot which does not braise the meat. Slow cooking makes the meat tender braising locks in flavor. Adding vegetables to the crock pot would also give it flavor. Sometimes I par boil vegetables before placing in pot because I like them soft. It is all up to your taste.