A number of limitations have limited my use of views again & again.
1. @Return(value) in a view column. Does that work even now?
2. Pivot / minor column-column connections between two views. It hasn't made a lot of sense to me why a Domino server would find it "tough" to connect two views across a specific set of visible views. In R3 (or was it R4?) we used to do something like this with search portfolios. Connecting up data ain't that hard -- again, granted the limited lists selected in a Web form. Limit it; use it.
3. Using profile document field values to translate information (e.g., dialog translations, statuses that need to be configured) in views also seems to be a big, needed feature. The profiles are cached documents, are they really that hard to use in a view?
4. Support alternate view sorting even when it's used with "aligned" view columns (unsorted, "display as multiple values" columns). This is a longstanding issue with a number of view designs.
5. Support alternate view sorting from XPages even when you're alternate-sorting only in "Descending" mode. For some reason this doesn't work in the view controls.
6. Allow ?ReadViewEntries to read the **entire** view for some calls. Yeah, it's going to push some data around. But to perform reports it needs to happen.
7. Allow ?ReadViewEntries to display the entire contents of a field or view column, not just what it's limited to in a normal view.
I don't know which of these features would be more useful. I just know I've run into them.