Back in the 90's, when it was possible for the maintenance folks to easily adjust/lower the old skid brakes, I had the opportunity as an employee to take a spin on the Beast with all the brakes off. They occasionally did this early in the year in preparation for the start of the season to "break in" the ride.
Having ridden it in normal operation hundreds of times, I can honestly say the most impressive part of the experience was the amount of speed the ride is capable of in the section between the break shed and the second lift (in the sections of track where the ride hugs the ground). The lack of breaks on the first drop didn't add a whole lot to the experience (although it did allow for the smallest pop of airtime in the back seat on the hill as you come off the first drop). The helix felt a little faster, but mostly a dramatic increase in roughness.
Having ridden it without the breaks, I definitely think they are necessary (as much as I hate to say it) for the comfort of most guests and for maintenance purposes - I could see some of the turns needing yearly rebuilding if they let it go "full throttle." And while the speeds today are generally the same as when the skid breaks were used, I just think they are more noticable because of the magnetic trims. The skid breaks slowed more gradually, as opposed to the sudden "grabbing" feeling of the magnets.