If it works, there should be no reason to worry.
As to sweating - it's a combination of cold water in the tank and moisture in the room. That's why our plumbing code requires either a window or a fan to remove moisture. I worked on one today that had no fan, and being winter, the window was closed. The tank and bowl were both heavily coated with condensation.
I wiped it all off and opened the window to dry it up.