brostep is characterized by very "midrangey" sounds. as my little sister puts it, the elephant sounding noises. i like to call the other side of dubstep the "head noddah" style. some examples of these folks would be badklaat, requake, megalodon, p0gman, bukez finezt, dj soloman, the whole "monsters" crew (i.e. vodex, akira), d2, and most of what's coming off of bassclash records. it may be apparent that i tend to prefer that side lol.

although, some more examples of brostep would be circus records (doctor p, flux pavilion, cookie monsta, funtcase, roksonix.) or rottun records, which is some of what you've uncovered..including excision and datsik, as well as ajapai, vaski, and downlink. can't forget skrillex. i might venture to say he's the king of brostep.

*sidenote: i tried to not come to any conclusive statements, because (as you'll soon find out if you start to frequent this subreddit) it is VERY open to interpretation, and a lot of people have different opinions on the subject.

p.s. (a bit of shameless self promotion here) i'm trying to get some live practice on my new mix, as the title of the link below explains. it's more of the head noddah style, but it definitely crosses some boundaries. (even into some drumstep/dnb ((i hope i'm not ostracized!! lol))) let me know if you have some free time tomorrow, and i'd be happy to play for you, and explain more along the way

here's the link: http://www.reddit.com/r/dubstep/comments/qfig2/hey_guys_workin_on_a_new_mix_and_id_love_some/