You should get to be a good enough writer so that you can write quickly and well for routine tasks. Your worst writing, in other words, should be good enough for you to get by. I think of this as my blog style: good enough not to be embarrassed by on the blog, but lacking the refinement that would come through serious revision and editing. Writing on blogs since 2002 has given me a certain facility for this kind of writing.
A review of an article that only the editor and the author will see does not have to be as refined as a tenure letter perused by many committees. The tenure letter can still use boiler- plate phrasing like "serious contribution to the field" as long as it is clear, forceful, and concise. The blog post can be more casual and might even include jocular tmesis like "a whole nother thing." I personally would not use "thusly" ever, even in the most casual blogging or emailing. When I see this word in a dissertation, I go crazy. "Thusly" is not an acceptable word in academic writing.
The base style is your best, ordinary writing with nothing fancy added; a style easily improved upon with minimal revision, but still adequate for basic communication.
