David,
What sort of build will you be doing to support Analysis Studio? Will you be having a dimensionally modelled data warehouse?
Will the users have their own area for creating reports?
From what I have seen / experienced Analysis Studio can replicate everything that powereplay can do so long as the data behind is dimensionally modelled, if the data is not then the users would not be able to 'Drill Down' through categories and only return the data at the lowest level.
I've currently been creating a Data warhouse utilising data manager to support our client base and have identified that two types of table are required, dimensionally modelled table, with hierarchies for analysis perposes and non dimensionally modelled data for flat file reports.
Query Studio, Report Studio, Analysis Studio are all important tools and can manipulate data in different fashions.
I've found Query Studio to be an excellent tool for demonstrations as I ensure that the client knows that this is the simplest tool for reporting and is quick.
Selling points for Analysis studio is that there is no wait time for cubes to build, customisable reporting, easily modified, excellent functionality and a cleaner userface, 1 click drill down, 1 click drill up. It's all down to dimensionally modelled data.
I hope my ramblings were helpful in some way.
Dan