Changing your legal software supplier has always been difficult and on occasions, acrimonious. Each software system will have different ways of setting up clients, names and addresses and other characteristics, entering financial information, managing the handling of cases (with different case management systems), managing the security of the data, restructuring management reports, how long to keep “old” data, stylistic matters in all reports … and so on.
This has always involved major efforts from the law firm in the preparation of data ready for transfer, and from both the original software company and from the target software company. Each side has to “understand” the other side of the operation and convert or structure the data accordingly. It has been, and still can be, not only a difficult operation but an expensive one. It is certainly a good idea to make absolutely sure that your existing supplier cannot provide what you want, before embarking on the process of changing supplier!