A top on an RT10----You don't need no stinkin top on an RT10, you want to hear the beautiful exhaust notes singing to you and all the sounds of the open road, not to mention the wonderful smells of summer like new mown grass, dead skunks in the middle of the road, etc. However, having the top on it does seem to make it a fair bit quieter inside when it gets cooler, the radio can even be turned down a few notches for sure. With the top and the V Mania windows on, I can even hear my wife talk in a volume somewhat lower than an actual shout as well. When the top is off, you really need an intercom system to talk to the person in the seat next to you, once you go over 50 mph or so.
But you know what, who cares, it is great just to cruise with the top off in the summer, but make sure you wear a hat, especially if you are folliclly (is that a word?) challenged like me. You don't want to cook your last active brain cell while out for a summer's drive.
******* is the only way to go.