Schedule Comparison (Claim Digger) is now in 16.1 Visualizer.

The Schedule Comparison tool that used to be called Claim Digger, is now housed in the 16.1 Visualizer tool that launches off of the P6 Client (Professional). You select it from the top menu. In the next screen you will select the project you want to compare and whether you want to compare it to a baseline or a copy of a project (most likely an earlier version since the "project" will be the current project). Credit to Randy Cash.

Have anyone used P6 Visualizer to create TSLD & Gantt Chart?

I would suggest using a sample project and only using one project to build out the "samples" or templates of the TSLD or Gantt Chart. The tedious, but fun part, is customizing the look and feel of the chart or diagram to really get it to where you want. If you don't have a powerful machine, it may hang, but it does not hang on a machine with 8GB of RAM. So keep that in mind. In a quick google search, I found a partner's pdf on using the Visualizer. Hopefully it helps you get started...

http://www.drmcnatty.com/wordpress/wp-content/uploads/2013/07/June-2013-Tech-Webinar-Primavera-Visualizer.pdf