The transfer policy of the IRS is better laid out and is much more transparent and stable.
In Indian Audit & Accounts Service, the general rule is that you get transferred in 3–5 years from a station. Generally, this means you will have to move from one state to another because the number of stations you could be posted as Group A officer is limited ( mostly capital cities.
The guidelines that are available in the CAG website is not very thorough, but only lists the basic guidelines. In many cases, the posting is done without any consideration by Dy. CAG ( HR) or Principal Director ( Personnel). I’m not quite sure who precisely.
You can read the guidelines here.
https://cag.gov.in/sites/default/files/cag_pdf/Transfer.pdf
Compared to this, IRS provides much more stability in tenure. The transfer guidelines are well laid out and if you plan well, you can easily stay in a region for upto 18 years in your career. As far as stability in family life ( wife’s job, children’s education etc ) is concerned this can act as a good factor in favor of IRS.
The transfer guidelines if IRS is here
https://www.irsofficersonline.gov.in/documents/officalcommunique/1727200940445.doc