(constructed perspective)
as i understand it aggro v. tempo is
-a subtle distinction in terms of how these decks operate -- tempo plays a more interactive game, whereas aggro is concerned with goldfishing anyone before they get set up. you could call tempo control in this regard.
-some other ideas are that tempo needs to find 'answer' cards and will often ride a single threat to victory, where aggro more wants to curve out.
-tempo also requires some of the good cantrips (incl. gitaxian probe and the 3 big ones) to find its answers, and for this reason it does not exist in modern or in most standard formats.
-though aggro has trouble coming from behind, tempo is even worse at it, since if they elude the hammerlock they will kill you and your hokey-ass one-drops. tempo is better against ramp and combo, whereas aggro is better against control and beats the shit out of tempo.
-aggro plays few lands. tempo plays even fewer.
-tempo is based on the good ol' nickel-and-dime and is very incremental in accumulating its advantages ("swing for 3 with delver. vapor snag your guy, take 1. snapcaster, flash back vapor snag, take 1. swing for 2.") aggro will make a nacatl and then a goyf and god help you if you do nothing.
-tempo will often 1-for-1 people and is loath to throw away value. aggro don't give a fuck
-tempo will flip delver t2 with mana leak and leave it up. aggro will make a nacatl and then a goyf.
-a classic tempo card is
stifle. a classic aggro card is
wild nacatl. some instances of overlap are
lightning bolt and
wasteland.
-there's a continuum between the two when it comes to actual decks, but some towards either pole are:
tempo decks -- legacy RUG Delver, legacy old-school Team America (just to show that these kinds of decks did exist before delver), and ISD standard delver; aggro decks -- legacy Merfolk, standard Gruul, modern affinity.
the concept of tempo in games is more obvious ("so I played U for
unsummon in response to your sword equip to a 4-drop, and you're up a card but i'm up eight mana. can i kill you before the card disadvantage matters?") and it's an important part of
mtg's complexity. that window can be quite small in constructed, and since tempo decks are for the most part highly-developed decks that run a lot of 4-ofs from all across
mtg history, supporting it in a singleton cube strikes me as a poor idea.
in cube i think people say 'blue tempo' because the density of creatures is going to be pretty low due to the suckage of said creatures. plus the creatures worth running are typically not your heavy-hittin' loxodon smiter but the extremely annoying venser and man-o-war (exception for wake thrasher). there are other reasons, but those are the big ones.
that being said, jason! the threats aren't all on the order of lameness of serendib efreet. man-o-war and vendilion clique are classic 3's, and i don't need any extra incentive to run sower or venser or sakashima's student or riftwing cloudskate.
in my opinion blue tempo needs the following to be supported:
-at least 2x of the big three cantrips, for filtering
-a very high density of high-power-level fixing, for reasonable (non-U) threats
-a conscious promotion of the theme to the point where you'd have to start cutting other U cards that fit the Cube well. i haven't been able to figure out how to surmount this, so i don't really run with the theme.
is it worth it? i don't think so, but i'm hoping i'm wrong.