Thats difficult to suggest 
it would be best to use webi rich client in local desktop, rather than using it on server as iits a client based application 
Reason: Unnecessary logins on server need to be avoided. Its crucial that webi reports should not be saved in server desktop, which can lead to decrease in space.
The performance would increase to a very small extent as per the reasons; this is I would say a practice to avoid manual interventions on server on regular basis.