Letters in high-end interdisciplinary journals – how much do they weigh in a CV? Are they only for experts?

Question

Some journals, especially some prestigious ones like Science and Nature, have these types of articles called letters which are usually an opinion/argument on a certain topic, e.g., to point out something that has not been discussed or some new research direction to take in a particular field.

How much do these publications matter in a young scientist’s CV? Because they are not really based on a specific study. Or are these mainly for researchers who are considered an expert in their discipline?

Also, I am wondering if PhD students or postdocs are taken into consideration if they submit such letter to a prestigious journal, or if a senior scientist needs to be among the authors.

Example: Bushmeat Hunting As Climate Threat

Jedediah F. Brodie and Holly K. Gibbs 

Science 16 October 2009: 364-365. [DOI:10.1126/science.326_364b]

Answer 1

Pretty much anything in a very high-end journal is difficult to get there and reflects a judgement on the part of the editors that your contribution will be of broad interest within the field. Thus, it is likely to have a significant positive effect on your CV.

Moreover, depending on the journal the difference between "Letter" and "Article" is often of little significance. For example, in Nature, the difference is that a Letter is 1500 words and an Article is 3000 words. Since most Nature papers are really just the tip of a much larger iceberg of Supplementary Information in any case, this distinction doesn't really matter all that much, and probably few of your readers will even notice which of the formats your article is in.