interesting it says 7018's DC+ DC- and AC, most of the 7018's i have used dont work that well on AC, think the esab ones have just DC+/- on them and no mention of suitability for AC
for the majority of use 6013 are great and commonly available, easy enough to use. depending on the rods most are suitable for most positions except perhaps vertical down on the cheaper ones. you tend to get what you pay for with the likes of lincoln, murex, esab rods cost a far bit more than the cheaper weldability, BOC everyday rods, but generally worth the extra money if you want a good job.
7018's are nice if you can weld with them, much harder to restrike because they burn back inside the flux, but a far stronger weld.
missing from the list are all the special rods, stainless, disimilar and NiFe rods.