RRI feature is used totally for different purpose.
this is mainly to jump to source system and validate data and drill down at document level from summary level report in BW or to jump to detail line item query with BW itself from summary report.
so there is no question of performance .there can be ABAP program also there when we create jump to source system.so there can be some performance degrade..
If all this answers your question pl close this thread..
Thanks and regards
Kiran