The phrase "am rather concerned" is correct and usable in written English.
You can use it when expressing a level of worry or unease about a particular situation or issue.
Example: "I am rather concerned about the recent changes in the policy and how they might affect our team."
Alternatives: "am quite worried" or "am somewhat troubled".
I am rather concerned about how often these animals have health issues from constantly being handled.
From what I did glean from the Methods, I am rather concerned with the robustness of the identification of orthologous sets.
Writing in 1978 to E. M. Widdowson, head of the Dunn Nutritional Laboratory and then chairing COMA, he complained: I am rather concerned that so little practical progress seems to have been made in achieving some form of vitamin D fortification to prevent vitamin deficiency in Asian immigrants.
Michael LaFargue (1992) also argues that the Daodejing is not to be interpreted as as concerning some metaphysical entity called the Dao, but is rather concerned with self cultivation that allows one to have a transforming experience of deep and peaceful stillness within one's personal center.
Boyle was rather concerned about the support that some audiences gave to the anti-black and anti-hippie views expressed by his character in Joe and, in 1971, he refused the Gene Hackman role in The French Connection because he felt the film glamorised violence.
We are rather concerned with what the resulting number, i.e., correlation coefficient, means and how it should and/or should not be interpreted.
We are rather concerned with the attitudes of those who do carry out exploration, possibly with managerial support but essentially out of their own initiative.
Here, each player is rather concerned with the fractions of players simultaneously playing the same action, i.e., using the same channel.
Though known in Germany, the term sans papiers (paperless) is used less often than in other countries as the public is rather concerned with those who face deportation after orderly registration in an asylum procedure that led to rejection.
In general, however, the Commission is rather concerned about the negative impacts on the EU economy caused by international developments such as restrictions in raw material availability or increasing raw material and food prices (European Commission 2011a).
By contrast, the present paper was rather concerned with hypothetical Small-Now versus Large-Later questions and explicitly measured the relationships between two key parameters (constant time preference and present bias) and two smoking behaviors (smoking and cigarette dependence) according to a quasi-hyperbolic discounting approach using a large sample.
