CS Slingshot represents rapid "vertical" growth, in that you gain a lot of power - through technology, without claiming a lot of land.
The "opposite" would be rapid horizontal growth, to the point where the economy redlines. You have little technology, but a lot of land. This could be called the "Expansion Boom".
Generally speaking, the expansion boom beats the CS slingshot. It's more straightforward, it's more reliable, it's safer.
The CS Slingshot appeals to the "noobly" instinct to keep your science rate at 100%, for some reasons players tend to fear their economy dropping to 0% (heck, some fear it dropping below 80%). It seems to take many players a long time to understand that 3x the cities at 30%, researches the same speed as 1x cities at 100% (but with the former also giving 3x the production so you can do 3x as much with your tech). The "sweet zone" tends to be from 40% to 60%, higher indicates you should be expanding more.
There are many viable opening strategies which end up with the baseline research rate at 0%, researching primarily through representation specialists, or through sack income from warmongering (ie you capture some cities and use that cash to fund some research, as a supplement to what you pointy-stick directly out of the victims).
The only time it's really challenging to do so, is under adverse conditions. If your leader is not Organized, Financial, Philosophical, Charismatic or to a lesser degree, Creative, and if the map has very little coast, it's relatively easy to expand so quickly that you boom then bust, actually going into deep negatives and suffering strikes. But with smart research choice you can basically expand as quickly as you can [train settlers, workers and garrisons] and once you redline, stop expanding, and be able to pull up before the economy crashes. With BAD research choices (basically skipping over the fundamentals) you can end up with a collapsed empire.
It could be an interesting concept for a game, since it is something less skilled players tend to understand poorly (expansion speed is quite possibly the single best measure of skill).