What are some comparative studies on program termination verification tools?
As mentioned by nekketsuuu, SV-COMP has a termination category, and the Termination Competition has been going on for quite some time (there is some overlap).

It depends on what kind of termination you are interested in. This paper on AProVE gives an overview of that tool, which covers many of the techniques involved in general program termination analysis and types of programs that can be handled, though it does not really analyze the comparative strengths of different tools.

Sadly, I'm not aware of any modern overview paper that does this, which is unfortunate. The tool description papers of the competition participants for your category of choice would be a good place to start.