7 - Pencil Heaven?

Yes, the long-awaited (well at least 12 hours, anyway) next chapter in the debate on which type of pencil is superior has finally arrived. So, where do I stand when in comes to .7mm pencils you ask - glad you asked.

I stand in the middle ground, 'cause that's what 7 is to me - a jack-of-all-trades but master of none. It's a hybrid, existing in the functional space between 2s and 5s (though not between them on the number line - that's for all you pencil-wielding mathematicians out there) Despite this, I have a few 7s lying around the house, ready to lend their sturdiness to my less graceful writing tasks:

• Sudoku: Quite simply, 7s are made for Sudoku. Not prone to the thin, hard-to-erase-if-its-dark-enough-to-read slashes of a 5, a 7 is thick enough to leave its mark and still allow for a very clean erase. Anyone who was spent a while cruising through a Sudoku puzzle only to find a critical error in that last little box will appreciate the Ctrl-Alt-Delete ability of the 7. Now, if you're a Sudoku master who does your puzzles in ink - good on ya. For the rest of us mere mortals, a 7 is the way to go. So what about a good ol' #2? Well, I have done puzzles with a 2 - but the variation in line width as the 2 gets dull makes it harder to see all the numbers (see Obsessive Compulsive Disorder here).
  
• Flying: Whenever I am flying (as a pilot, not a passenger), a 7 is the sine qua non of writing things down. Pen ink freezes up when the cockpit gets chilly at higher altitude and I think the changes in air pressure affects ink flow as well. 5s are too delicate to stand up to furiously writing down the new flight plan clearances Air Traffic Control fires off while I'm trying to maintain altitude in bad weather. 2s are okay and popular among some of the older pilots out there (no mechanism to fail and less likely than metal mechanicals to jam flight controls if you drop it) but to me they have one fatal flaw in the cockpit - no retractable tip (necessary for avoiding punching holes in your clothing or leaving errant graphite trails on them).

So what is your view on the 7?