Financial Planning and Analysis (FP&A) Solutions vs X3 Out of the Box Financial Reporting

Up until the last couple of years as it relates to the financial reporting and analytical needs my clients seemed to have been satisfied with the out of the box budgeting and financial reporting capabilities that X3 has to offer and/or if they were looking for a more advanced solution they would go with a solution such as SEI or SI. 

Now I'm seeing a trend in clients wanting to integrate third party "FP&A" solutions.  I've done a very cursory study of what these softwares have to offer, but I would be interested in hearing the opinions of those of you more learned with that technology.  Specifically regarding the question of what they provide over and above what standard X3 and/or SEI have to offer.  

My initial perception on the matter is that X3 ticks many of the FP&A boxes (i.e. financials reports, budgets and forecasting, report distribution, etc).   

I would contend that whatever remaining gaps exist between X3 and a "full blown FP&A system" wouldn't be difficult to fill.

With those gaps being filled I think from a marketing perspective being able to bring to market an ERP solutions with a built in FP&A module would be something to make us stand out from the competition.