Frame braces work very well at helping even a standard VMax feel more planted and secure on the road.
Where I notice it most is in a long sweeper that has some undulations in the pavement. Pre braces, the bike felt really squirrely as it went over the bumps due to the frame flex. The flex allowed the line of the front and rear wheels to change just a little and cause the bike to "wiggle".
Post braces, the "wiggle is gone" and it is much more predictable.
Another option for sureing up the frame are solid motor mounts. Search and you will find tons of info on them as well as the frame braces. There are pros and cons to both.