Say you write a paper that you feel makes a borderline case for publication in a prestigious journal (Annals, Acta, Inventiones, JAMS, etc). What are the advantages and disadvantages of submitting the paper to the prestigious journal over a less prestigious journal where your paper is very likely to be accepted? My novice take is that there is little downside since if the paper is rejected you can always then submit it to a less prestigious journal. Are there factors I'm not considering? Of course, in most cases, the paper is Arxiv'ed early on so one's claim to the result is never hurt by a lengthy publication process.
I'd be interested to also hear about the implications on job applications. How much does it hurt a job applicant to have a very good result Arxiv'ed and submitted versus accepted? (Presumably if the validity of the result was a make or break factor for a job the hiring group could take a look at the preprint or talk to an expert in the field. Maybe that is an unrealistic expectation).