When considering multiple apps, it's important to understand both the benefits and detriments. The main categories I can think of off the top of my head would be time profile (weekly/monthly), dual maintenance, end users potentially having to log into both apps, keeping both apps in sync - not only from a metadata perspective, but also cube views, dashboards, business rules (that may need to be modified depending on how similar or different the apps are). One would think data movement is a big factor, but it isn't a major one.
None of the concerns mentioned in the OP (end user experience, aggregate vs consolidate, performance, metadata) would push me to two applications.