Whether to buy tools for financial reporting and budgeting/forecasting from the incumbent vendor is a question increasingly raised by folks we work with. The real question should be -- "At what point do we buy the brand name that we have existing investments with?"
For us, the issue centers on the short/long term benefits and the costs of any selection. Certainly, a red flag should be raised when there is lack of functionality in key areas. However, functionality is sometimes centered in the pros/cons and always subject to personal opinion. At the same time, many companies ask their finance teams to "do more with less" in order to lessen perceived "total solution costs" and benefit from "future integration".
With any investment in business process, the vendor is a key question. We insist our clients ensure integration will occur. Buying software integrated only at the "brand name" can be a dangerous activity.