I would like to see these things: backupset size, how long it took, compression ratio and backup type. Well, good enough, We can create Oracle SQL Developer XML extension (Oracle call it). I would rather name it as user defined report, compare to UDM (user defined metrics) in Oracle OEM Grid Control. It allows us to get report with Chart, Table. And such kind of UDR supports drill down and master-details in the simplest way. It is OK but is not powerful enough for DBAs to have more customized functionality.
I created such report as follows, looks good. Why not Oracle give us: RMAN> list backup size 2 days ago? hopefully they would think about this idea in next release. Otherwise, I have to create real SQL Developer extension by JDeveloper Extension SDK.
Simple but lot of rooms to improve by Oracle.