Great question.
For me, I would pay a premium if I could have a public online report matching the slab number. Something that included:
- List of authentication sources consulted. This might include prior public sales, internal repository of notes, or a specialist for a particular issue.
- Reasoning for an assigned grade (Similar to BGS, but with notes unique to card)
- EXACT card dimensions
- High resolution scans, with micrography if possible.
- Ownership/provenance registry (public or private depending on submitter's preference).
- Grader employee number, if not name. This would ensure any 'patterns' could be monitored by the hobby.
Would love to see a ton of optionality on slab presentation. In other words, could be a plain frame (submitter choses colour/style), or might contain information on front (grade, card number, year) as they do now. I personally would prefer a smaller slab, frame only, with any information on the reverse.
Finally - It would be great to have a company that is regularly willing to stick their neck out on forums and actually explain reasoning behind certain decisions or problems. Eg: "We missed these trimmed cards, here's why, and here is what we intend to do about it"........Or, "turnaround times are at 5 weeks, but here is how we intend to bring wait times down."