It seems like Oracle Application is a pain in the a**, my collegue is working with it and he has already applied about 25 patches in the last 4 weeks! Also I think you need pretty good knowledge on IAS since 11i is based on multi tier architecture. So I would think twice before want to get involve with Applications (I am forced to, next week my nightmare starts)

Ah!!! Then you have problems like integrating Discoverer with Applications (just to list one)