Surskit may have been available in almost the entire world but it was like a sub-1% chance encounter @_@; I got one immediately in OR though :D Even if it's garbage until it hits lv17 for bubblebeam... but the way the EXP Share works now makes deadweight pokemon like that a non-issue. (I haven't played since the actual ruby/sapphire emerald so this is a lot of new features! Catching pokemon is a lot more interesting and fun now)
But yeah, if you've ever seen a pokemon, the nav seems to display it. And then once you've caught one, you can just force a battle with it, making rarity a non-issue... neat! It's also kinda convenient for grinding since you can just pick the pokemon that you hit weaknesses on, but, grinding also seems like much less of a thing with how the EXP share works.
Mmmn, I might actually go for filling out the dex since it won't be hard to powerlevel things to evolutions. But I'm only in Dewford so that's a bit far away :V