- The wine's potential.
- The wine's structure.
- Sensory descriptors (optional).
- Score (optional).
A grocery list of aromas and flavors is purely optional unless they highlight how well a wine adheres to its archtype: currants and cigar box in Bordeaux, nuts in Meursault, etc. Clive Coates manages very well without them.
A feel for the wine's structure and style is paramount. At least tell me if the wine is in a modern style or not. The British writers (as opposed to Robert Parker) do this quite well.
What I value the most is what a writer who knows the wine or region or producer better than I do tells me about the wine's potential and how long it will live. By now, I'm fairly adept at figuring out how good a given wine is now (assuming it's past its early infancy, anyway) but I want to know more about what it will be like as an adult, especially when to open it.
Style-wise, I like some poetry and creativeness if it doesn't obscure the above points. My reasoning is great wines (even great little wines) should have an emotional effect of the taster. I don't enjoy reading notes by jaded tasters who can't be moved emotionally.
PS. Size doesn't (always) matter.