If you've written an excellent paper, that's still no guarantee that it'll get into the prestigious general journals (such as those listed in your question). For example, the editors or referees might declare your topic to not be of general interest. If this turns out to be the case, you should consider publishing in a prestigious specific journal (not necessarily a less prestigious journal).
The worst possibility is the long rejection -- that is, having a paper refereed for a year or so, only to be rejected. This seems to happen a lot with the general journals as the referees are trying to maintain a high standard (and the editors can't always tell if a paper is worthy or not). The refereeing process is confidential, so the only downside is time wasted, and you might get some excellent feedback too.
For job applications, it's much easier for a potential employee to gauge the merit of a general journal (LMS, AMS, etc.) then a specific journal. They can be 100% a result published in these general journals is decent, regardless of which field they are in. Whereas, it can be difficult to explain the importance of a specific journal.
I heard from one university that they had 600+ applications for one position. If the hiring committee looked at one application per minute, they would still take 10 hours. They won't have time to look at arXiv, chat to colleagues, etc. for the vast majority of applicants. Moreover, even if the paper is on the arXiv, unless the committee are experts in your field also, they won't know whether or not your paper is decent. You can explain the merits of your work in-person at a job interview.
Having a paper on the arXiv (vs. not having it on the arXiv) counts for nothing in job applications. Generally, you want not-yet-accepted papers listed as either "in preparation" or "submitted".