I shave with straights, shavettes, DEs and the Cobra Classic and I don't get BBS with any of them. I can get 90% of a BBS with a DE (with more irritation than I want), but am much happier with the goal being a DFS. The Cobra gets the closest cut (using the Feather Pro blade) followed by DE, shavette and straights. Why are straight last, because they aren't as sharp as the best disposable blades. I don't get a DFS (at least what I call a DFS) from a straight on my cheeks or anywhere else. I learned using DEs and I ended up using Feather and Super Iridium blades because most blades can't cut the beard around my mouth without pulling. In fact a couple of brands (which will remain nameless) did not pull when they reached my chin, they stopped cutting period.

It has been said that sharpness makes up for some poor technique, but that seems to me to be saying it's tricky to shave with a duller blade. I certainly agree with that. If maintaining your blade at a level of sharpness required to cut your beard is beyond the time and skill level of the shaver, then using a sharper manufactured blade makes more sense. Of course, it is fun to try and build your skill set up to the point you need to achieve your goal. It is just significantly more difficult for those of us with very coarse beards.