Is it worth purchasing the VPI 16.5?

Because the string is replaced each time you use it and because the arm tracks the gooves, I would strongly recommend the LoriCraft record cleaner imported by Smart.

I have owned several VPI and NG cleaners. In each instance where I further clean a record previously cleaned on the VPI, I hear a substantially quieter and more transparent sound after cleaning with the LoriCraft.

There clearly are variation among record cleaners in their effectiveness. You may be satisfied with less effective cleaning or you may not. In part this probably depends on the quality of your vinyl front end.