There are several analysts that cover the core banking space: Gartner and Forrester for example. There are also online comparisons available.
Having spent some time reviewing these points of view and assessing core banking systems directly, the important thing to consider is where the organization is coming from and what it is looking for. Each system and company is different and offers a unique perspective on the solution.
When it comes to core banking solutions, one size certainly does not fit all!