I think it's largely going to depend on on the job, as a cover letter tends to not be a great place to give context as to technical aptitude or skills as much a

I think it's largely going to depend on on the job, as a cover letter tends to not be a great place to give context as to technical aptitude or skills as much as it will to demeanor and presentability. The former is much more important for engineering positions, the latter for front-end folk that deal more directly with users. That is not to say that there is never any cross-over of the skill sets between the two, but you really don't want to have the "Nick Burns, your company's computer guy" dealing with social stuff if you can avoid it.