Great work, Jacob. This is the article that really puts the concept of "Tempo" into a sensible framework that is easy and logical.
If you spend too much time drawing cards and not enough investing in Tempo, you will be too far behind your opponent to have any chance of recovering and winning the game. This isn't always the case, and Card Advantage is often crucial for control decks to preserve their Tempo advantages, but it is an important trap to watch out for. I've seen too many Vintage decks that try to pack in upwards of 16-20 draw spells, and then just keep drawing cards until they lose. If you can convert all of those cards into some ridiculous Tempo, fine, but if your basic gameplan is the same as another deck, you may need more answers to slow your opponent's Tempo, instead of just more card drawing.
One exception to this are decks that try to win with a two- or three-card combo finish. Combo decks have shifted towards Storm combo and Oath, which are not working like combo decks of old. The example I have in mind are the Stone Keeper decks of old, using Power Artifact and Grim Monolith with Stroke of Genius or Braingeyser to end the game in a flash. Of course, Stone Keeper had removal and stuff, but sometimes gave you hands that enabled just the gameplan: Draw lots of cards or find the pieces with Tutors (which were usually a tempo-setback) and then explode from a position far behind. When you have the ability to convert two cards into "some ridiculous tempo", it's worth giving up as much as you can before losing.
Also, tutors have an interesting spot in your tempo theory. In case of Demonic Tutor, it transforms a card and two mana into a card. The Mirage tutors are a even worse deal: two draw steps, a card and a mana into one card. That means iof you want to keep up tempo, you need to find something that exchanges positively (like Ancestral Recall, Time Walk, Will etc.). This also explains why tutoring for Brainstorm with Mystical or Vampiric is usually a bad move.
As for the land drops, this is very true, but you also need to figure out when maximizing your mana means holdingback for Drain. That is one of the major decisions of Meandeck Gifts, btw, and one of those that make the deck so hard to play correctly.
Again, great article, Jacob!
Dozer